AG wizard does not run sp_control_dbmasterkey_password for databases with DMK.
There is a bug with AG add database wizard for databases with DMK, it does not run spcontroldbmasterkey_password on replicas as expected.
In the AG Add database wizard, if you select:
'Full Database and Log Backup', it works as expected, and the credentials are created on the replicas.
'Automatic Seeding' to add the database, it does not run spcontroldbmasterkey_password.
If Automatic Seeding is selected, in the validation check "Checking password of the database master key", it says it has skipped it because: "Skipped Checking password of the database master key because you skipped initial data synchronization."
Verified up to SSMS 18.1