couldn't drop subscription after upgrading via logical replication.

Hello!

I upgraded my postgres from 11 to 13 using logical replication(publication in PG-11 and subscription in PG-13 of course).

Now I encountered this problem, I cannot drop the subscription in PG-13:
drop subscription sub_upgrade_to_13;
ERROR:  could not drop the replication slot "sub_upgrade_to_13" on publisher
DETAIL:  The error was: ERROR:  replication slot "sub_upgrade_to_13" does not exist
The thing is that I already stoped my PG-11, there's no way I drop the replication slot "sub_upgrade_to_13" on publisher,
is there anything I can do to solve it?

Many thanks!