Chickens Glitching in an Arch (3block out 1 block down 200 blocks at least) from a auto chicken farm. noticed it after we defeated the Ender dragon on local server after the 1.16.100 update. have removed all mods and ever reset local server issue remains and multiplies when reloading the chunk

Back ground:

this farm has worked fine no issues for about 3 weeks before the latest update.

Issues:

Now glitching chickens are causing major lag, they cannot be interacted with an are unable to be removed from game.  

side note and Probably separate issue also caused one of our local units can no longer load update or download Minecraft since the update. all specs are in line and was working up until the release of 1.16.100 error