When checking the logs of the Storage Replica on a Windows Server 2016, 2019 or 2022, using the below command, you get the error saying that Storage Replica has failed an application IO.

Get-WinEvent -ProviderName Microsoft-Windows-StorageReplica -max 20

In this case, the replication is not working and there are no other issues pointing to what could be the problem. In my case the solution was to restart the Storage Replica service from the services.msc. After this, I ran the Get-WinEvent command again and it was replicating again.