Sorry but I returned the router as the speeds were not enough for my use case. As noted, from what I can remember I went to Network>wireless>scan, scanned on the 5G radio, filled in the right security info (protocol on auto, peap mschapv2 I think, id, password, TLS encryption), then connected. I had disconnection issues, but pinned that down on disconnection packed sent on the network and turn on the setting ignoring them.
If I remember well, the first time it didn’t work for unknown reasons. I had to reset the router and redo everything. However, on the second try everything went well. Except for the speed everything was stable and worked like a charm.