Still an issue in 1.20.1! I know it isn't detrimental to the game, but this is EXTREMELY annoying for people trying to make it have a very specific order
Just had this bug as well! The issue seemed to happen after I made a mangrove tree with /placefeature and used the command "/fill ~-10 ~-10 ~-10 ~10 ~10 ~10 air replace #leaves" and "/fill ~-10 ~-10 ~-10 ~10 ~10 ~10 air replace #logs". Happened within less than a second of me using these commands and then breaking the mangrove propagule that I had placed down. Not sure if these are directly correlated, but it sure seemed that way to me
Worth noting that while datapacks cannot normally do this, they can still be set! Here's the method:
Forceload a chunk
Set one of the blocks in that chunk to a repeating command block running the desired command
set the block back to what it previously was
un-forceload the chunk
Mostly just a band-aid fix until they fix it themselves. Hope this helps