Merged Mobs

I know lots of reports have been coming in about lag about this, but this is something different. The mobs won't combine, some of them do and some of them don't
TannerLittle
CypriotMerks

 

I don't think already merged mobs merge with other merged mobs. (I hope that makes sense. Basically, unless they are singles, they don't merge together.)

 

Lets say there is a chicken 2x and another chicken x8 they can combine since I saw it lots of the time. It's just something with these 2 chickens, all the other ones work and sometimes some of them don't.

 

Hm, I couldn't get like 6x cow and 4x cow to merge.

 

That is what is happening to me, but some of them merge while some of them don't.

 

I don't think it is possible for a Mob to merge to other when they have already spawned.

 

It is possible, I have done it many times, but for some reason sometimes it does not work.

 

This still a problem?