I traced the "can't connect crypto wallet from iOS to macOS" problem a bit: I captured this error from the iOS device, which seems to suggest it couldn't find the matching key posted from the macOS laptop side for the pairing, i.e., the qrcode gets posted to cryptowallet.opera-api.com from macOS and the iOS tries to go match with it but is failing. 
I'd have to go trace the wire, but it seems like something basic.
Opera versions
iOS: 2.5.1
macOS: 72.0.3815.400
P.S. I happened to triple-tap on Version in Settings and found this, so I do have a full log.
