sometimes when I join a server, the rendering gets messed up. I only tested this in 1.8.9, so this bug may not be in the newer versions. I think this is caused by joining in third person, could be wrong.
Normal:
Bugged:
tr7zw commented
Note that 1.8 is not supported really. Looks like its mixing up the Steve and Alex arm sizes, but not much I can do there rn.