Somehow your secondary is not part of cluster node that what it look like from snapshot you have uploaded.

Please make sure it is part of cluster.

Just check in event viewer...

alter database <Database name> set hadr off

what error are you seeing in event viewer ? related to windows cluster ?

You need to kill those session which are trying to connect to your replica.

and then try to drop it.

or

kill those session and restore database with recovery and then drop...

Thank You Gail.