We're seeing the following error fairly often (as in a few times per day):

ERROR: replication slot "msg_slot" is active for PID 8990 (SQLSTATE 55006)

We're using AWS, but the DB usage isn't particularly heavy. We fetch the changes using this query

select data
from pg_logical_slot_get_changes ('msg_slot', null, null, 'add-tables', 'public.product')

One thing that I thought of is that we have two instances running this query every 30s. Could that be the cause of it?