EGIRP issues on Router Sub Interface .. Convergence Takes longer ..

Hello Evereyone  , 

I am going to through  Brian's INE CCNP route (EIGRP) recording and I have same INE real LAB and during my EIGRP lab practice i notice that convergence takes longer over sub interface when switch is in the middle same topology as in INE CCNP EIGRP class .

and when I search on Cisco forum , is says that EIGRP work different over LAN . So what I can think of is when we shutdown sub interface on router but main interface is up so EIGRP wait for hold time expire and then switch over to FS . how we can fix that ? 

can we just move to main interface ?  sub interface is same as router on a stick to make any to any connectivity .. 

Please advise 

Thanks