Secondary Replica can not be joined again

Question

I had three replica in my availability group without cluster. The installed SQL Server version is:

Microsoft SQL Server 2019 (RTM-CU14) (KB5007182) - 15.0.4188.2 (X64)
Nov 3 2021 19:19:51 Copyright (C) 2019 Microsoft Corporation Enterprise Edition: Core-based Licensing (64-bit) on Windows Server 2019 Datacenter 10.0 (Build 17763: )

One primary (let's call it A) and two secondary (B & C). At first it was only (A & B). After some physical issue occurs in primary server we prepare server C to replace it with Server A. So At first Server C joined to availability group as Secondary sync replica like Server B.

Then we do a failover wizard manually on Server C. Now the role of Servers A and C changed correctly. Server C became primary and Server A became Secondary. The problem is that after failover the another Secondary was not syncing any more.

We couldn't solve the problem and decided to remove the replica and join it again with initiating databases. First of all we remove the replica from primary server. At this time we understand that Secondary replica (Server B) is not aware of the fact that has been removed from availability group. So we could not add this replica again.

I tried these steps:

1. disable AlwaysOn
2. restart SQL Service
3. restart Windows
4. enable AlwaysOn
5. restart SQL Server again

But still the problem exists.

Answer 1

I solved the issue by removing availability group by running this code in Secondary replica:

REMOVE AVAILABILITY GROUP [ag-name]