7.17 BGP Auto-Summary

I don't understand why BB1 and BB3 are receiving the /24 for the 150.1.x.x whereas they are receiving only the /16 for 155.1.x.x... both were advertised into IGP as /24 so with BGP auto-summary enabled all I need is a classful statement (i.e network 150.1.0.0 and 155.1.0.0) for BB1 and BB3 to receive /16s rather than /24s, yet it's only working for the 155.1.x.x networks:

R6(config-router)#do sh run | s router   
router eigrp 100
 network 150.1.0.0
 network 155.1.0.0
router bgp 100
 bgp log-neighbor-changes
 network 54.1.1.0 mask 255.255.255.0
 network 150.1.0.0
 network 150.1.6.0 mask 255.255.255.0
 network 155.1.0.0
 neighbor 54.1.1.254 remote-as 54
 neighbor 150.1.1.1 remote-as 100
 neighbor 150.1.1.1 update-source Loopback0
 auto-summary
R6(config-router)#do sh ip bgp neigh 54.1.1.254 adv
BGP table version is 27, local router ID is 150.1.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>  54.1.1.0/24      0.0.0.0                  0         32768 i
 *>  150.1.0.0        0.0.0.0                  0         32768 i
 r>i 150.1.1.0/24     150.1.1.1                0    100      0 i
 r>i 150.1.3.0/24     150.1.3.3                0    100      0 i
 r>i 150.1.4.0/24     150.1.4.4                0    100      0 i
 r>i 150.1.5.0/24     150.1.5.5                0    100      0 i
 *>  150.1.6.0/24     0.0.0.0                  0         32768 i
 r>i 150.1.7.0/24     150.1.7.7                0    100      0 i
 r>i 150.1.8.0/24     150.1.8.8                0    100      0 i
 r>i 150.1.9.0/24     150.1.9.9                0    100      0 i
 r>i 150.1.10.0/24    150.1.10.10              0    100      0 i
 *>  155.1.0.0        0.0.0.0                  0         32768 i
 *>i 204.12.1.0       150.1.4.4                0    100      0 i
 *>i 205.90.31.0      155.1.0.2                0    100      0 200 254 ?
     Network          Next Hop            Metric LocPrf Weight Path
 *>i 220.20.3.0       155.1.0.2                0    100      0 200 254 ?
 *>i 222.22.2.0       155.1.0.2                0    100      0 200 254 ?

Total number of prefixes 16

R4(config-router)#do sh run | s router
router eigrp 100
 network 150.1.0.0
 network 155.1.0.0
router bgp 100
 bgp log-neighbor-changes
 network 150.1.0.0
 network 150.1.4.0 mask 255.255.255.0
 network 155.1.0.0
 network 204.12.1.0
 neighbor 150.1.1.1 remote-as 100
 neighbor 150.1.1.1 update-source Loopback0
 neighbor 204.12.1.254 remote-as 54
 auto-summary
R4(config-router)#do sh ip bgp neigh 204.12.1.254 adv
BGP table version is 27, local router ID is 150.1.4.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 *>i 54.1.1.0/24      150.1.6.6                0    100      0 i
 *>  150.1.0.0        0.0.0.0                  0         32768 i
 r>i 150.1.1.0/24     150.1.1.1                0    100      0 i
 r>i 150.1.3.0/24     150.1.3.3                0    100      0 i
 *>  150.1.4.0/24     0.0.0.0                  0         32768 i
 r>i 150.1.5.0/24     150.1.5.5                0    100      0 i
 r>i 150.1.6.0/24     150.1.6.6                0    100      0 i
 r>i 150.1.7.0/24     150.1.7.7                0    100      0 i
 r>i 150.1.8.0/24     150.1.8.8                0    100      0 i
 r>i 150.1.9.0/24     150.1.9.9                0    100      0 i
 r>i 150.1.10.0/24    150.1.10.10              0    100      0 i
 *>  155.1.0.0        0.0.0.0                  0         32768 i
 *>  204.12.1.0       0.0.0.0                  0         32768 i
 *>i 205.90.31.0      155.1.0.2                0    100      0 200 254 ?
     Network          Next Hop            Metric LocPrf Weight Path
 *>i 220.20.3.0       155.1.0.2                0    100      0 200 254 ?
 *>i 222.22.2.0       155.1.0.2                0    100      0 200 254 ?

Total number of prefixes 16

BB1#sh ip route bgp
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       + - replicated route, % - next hop override

Gateway of last resort is not set

      28.0.0.0/24 is subnetted, 2 subnets
B        28.119.16.0 [200/0] via 172.16.4.3, 03:32:05
B        28.119.17.0 [200/0] via 172.16.4.3, 03:32:05
      150.1.0.0/16 is variably subnetted, 10 subnets, 2 masks
B        150.1.0.0/16 [20/0] via 54.1.1.6, 00:01:01
B        150.1.1.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.3.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.4.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.5.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.6.0/24 [20/0] via 54.1.1.6, 00:01:01
B        150.1.7.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.8.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.9.0/24 [20/0] via 54.1.1.6, 00:00:30
B        150.1.10.0/24 [20/0] via 54.1.1.6, 00:00:30
B     155.1.0.0/16 [20/0] via 54.1.1.6, 00:01:01
B     204.12.1.0/24 [20/0] via 54.1.1.6, 00:00:30
B     205.90.31.0/24 [20/0] via 54.1.1.6, 00:00:30
B     220.20.3.0/24 [20/0] via 54.1.1.6, 00:00:30
B     222.22.2.0/24 [20/0] via 54.1.1.6, 00:00:30

BB3#sh ip route bgp
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       + - replicated route, % - next hop override

Gateway of last resort is not set

      54.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
B        54.1.1.0/24 [20/0] via 204.12.1.4, 00:06:39
B     112.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     113.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     114.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     115.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     116.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     117.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     118.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
B     119.0.0.0/8 [200/0] via 172.16.4.1, 03:37:59
      150.1.0.0/16 is variably subnetted, 10 subnets, 2 masks
B        150.1.0.0/16 [20/0] via 204.12.1.4, 00:06:39
B        150.1.1.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.3.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.4.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.5.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.6.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.7.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.8.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.9.0/24 [20/0] via 204.12.1.4, 00:06:39
B        150.1.10.0/24 [20/0] via 204.12.1.4, 00:06:39
B     155.1.0.0/16 [20/0] via 204.12.1.4, 00:06:39
B     205.90.31.0/24 [20/0] via 204.12.1.4, 00:06:39
B     220.20.3.0/24 [20/0] via 204.12.1.4, 00:06:39
B     222.22.2.0/24 [20/0] via 204.12.1.4, 00:06:39

Thanks in advance!!!