I am playing in 02/08/19 in Java Edition, 1.13.2 version, this also happens to me. After I returned to the game I had saved and left I found my 2 tamed wolves sitting and could not make them stand up again. I had not commanded them to sit before leaving the game and the puppy that was with them was not there anymore, simply dissapeared. I can still feed them though, just can't make them stand up and follow me.
Mateus Giovanni
I am playing in 02/08/19 in Java Edition, 1.13.2 version, this also happens to me. After I returned to the game I had saved and left I found my 2 tamed wolves sitting and could not make them stand up again. I had not commanded them to sit before leaving the game and the puppy that was with them was not there anymore, simply dissapeared. I can still feed them though, just can't make them stand up and follow me.