The bug
Blocks (affected by randomTickSpeed ?) do not update anymore.
Additionally to this saplings, apples and sticks are dropping around 20 -30 blocks away from leaves that aren't decaying
For a similar issue in multiplayer with 2 or more players, see MC-137795.
Affected
leaves not decaying
farmland not hydrating
crops not growing
...
Linked issues
Comments 3
I made this the parent report for all duplicates about the same problem. Therefore it now includes the other cases of blocks not updating as well.
All of these things are functioning; instead it updates elsewhere in the world (MC-139693).
Apparently I made two of this exact bug report