Im not entirely sure, but clag may be picking up your item frames D:

Well a bunch disappeared this time. not all of them. I know painting get picked up with clear lag, but it seems they disappear when I'm within the chunk. I haven't tried them with items in them just yet.

My rainbow sheep disappeared today Q.Q tis behind glass. 2nd time this has happened.

Oh my... Very strange. :/ I dont know any reason why that would happen x.x

It has been about 2 weeks since this one has been alive. The item frames seem to not disappear when holding items so that is a simple solution but my disappearing sheep is a mystery (There are fences but not 100% surrounding but 1 has yet to disappear)

Welp, leave it to me to be completely confused about net stuff..