When leaving some items to cook while exploring other areas on a private server, I noticed the items were gone, and the furnace and smoker were left bugged in their lit state. I looked into the logs, and saw errors claiming that the server failed to load the block entity when I returned and reloaded the chunks. Relevant log snippet attached. Some recipe datapacks are enabled on the server, but none of them touch the recipes affected. Not explicitly tested with blast furnaces, but I believe I remember something similar happening earlier in the playthrough when smelting raw iron.