In new Exploration on my home map, I attached a couple goats, horses, and sheep to some animal pens in a blueprint-constructed barn, and 2 minutes later, they were gone. I could no longer see them attached to the animal pen (seeing the animals themselves, or within the animal pen menu, or within the animal section of the radial menu). I also had some chopped down trees (wood, resin, etc) laying around nearby if that could have caused lag, or something. I tried to tame some new animals, and it wouldn't let me pick up the bait. It just said failed. I did not think to get output logs for this. I tried restarting the game, hoping they would reappear but they didn't. I then rode some other animals into the barn without attaching them to an animal pen.
Two of them also disappeared around the time I tamed 2 sheep and I grabbed the output logs.
These last three seemed to be more stable and haven't disappeared yet. The goat had been ridden into the barn, but I left the two sheep outside.
output_log_clean.txt
output_log.txt