Database had been improperly configured as standalone (no in AG group) on Node C.
To fix the issue I did the following: I backed up database and detached from Node C.
Node C is now and was also at the time a secondary in the AG group.
Went to primary Node A restored database onto Node A, added database to AG group, initially got error regarding Node C..I had to delete file database.mdf from Node C and then AG wizard succeeded. Now the restored database has synchronized to Node A and B, but it's failing on C. Error on restored database in AG dashboard of Node C states the following:
Data synchronization state of availability database is not healthy.
What is the proper procedure to handle this issue? Help? Please and thank you.