Access points

We had two Sophos access points which kept saying inactive and no matter what we did couldn't get them active, so we deleted them from XGS and factory reset the two access points (held reset for 30 seconds) but now they're not appearing in the XGS at all under pending.

Is there some stale record I need to delete from the CLI or something to make the Sophos XGS pick up the factory reset APs ?