Availability group issue

Good day ,

Sql AlwaysOn has been around for over a year and works very well recently. The database server lost the network connection twice. The switch takes place twice. Everything works fine, but I have a strange situation. All databases are synchronized to primary and secondary added the configured availability group, even if the listener is available. You can see below that no database is added to the secondary replica.
I tried to add the database to secondary replica but i get message that Already part of an avaibality group

Can you please help to fix this issue

Many Thanks


Regards