We have 2 AlwaysOn servers running on 2 different sites (Site1 and Site2), with the secondary replica NOT READABLE in Site2. All backups are performed on the primary replica in Site1. I have found that AlwaysOn always failover to Site2 on Monday morning, making the replica in SITE2 primary and the replica in SITE1 secondary. I am still troubleshooting why the failover, but this is not my question so far.
What I would like to know if there is anyway I can setup so that if the original primary replica (in Site1) is seen as ONLINE and reachable, the AlwaysOn will always failover back to the original primary replica from Site2?