Sometimes when a contraption (in this case a tree farm) gets unloaded and needs to be restarted can cause some parts to be replaced by leaves if there are grow trees around it.
create-mc1.16.3_v0.3e

This issue has been marked as stale because it has been inactive for 3 weeks. It will be closed if it remains inactive for another 3 weeks.

This issue has been closed since it has been inactive for 3 weeks since it was marked as stale.