Stop seeding process in the AG
You can stop automatic seeding by setting seeding mode for that secondary replica to &quot;manual.&quot;  This will stop seeding for all databases.
See this docs article for the details: Use automatic seeding to initialize an Always On availability group - Stop automatic seeding

To stop automatic seeding for an availability group, run the following script on the primary replica:
ALTER AVAILABILITY GROUP [&lt;availability_group_name&gt;] 
MODIFY REPLICA ON '&lt;secondary_node&gt;'   
WITH (SEEDING_MODE = MANUAL)


Once seeding has been stopped, double check that the &quot;problem&quot; database has been removed from the AG (and is removed from the secondary), and then restart seeding:

You can set automatic seeding on an existing database. The following command changes an availability group to use automatic seeding. Run the following command on the primary replica.
ALTER AVAILABILITY GROUP [&lt;availability_group_name&gt;] 
MODIFY REPLICA ON '&lt;secondary_node&gt;'   
WITH (SEEDING_MODE = AUTOMATIC)


From your question, I'm not sure if you deleted the problematic database from the primary server, or if you just removed it from the AG.