Just to update on this saga...
It got resolved. One of his banks accepted I was a bona fide Wise account owner, and made a DD withdrawal and deposit on my Wise $ account as a verification procedure. His other bank remained unconvinced, as in the US, property sales are finalised by a titling company who pay out the agreed amount(s). But this system doesn't exist outside the US, so the bank cried foul when my friend tried to pay me direct.
One thing of note. The bank that made the DD micro withdrawal and payments was able to set up the DD without any notification to me. Meaning they could have helped themselves to any amount in that account. I protested vehemently to Wise claiming this looked like a massive security hole. After many emails, they disabled DDs on all my Wise accounts for withdrawals. Incoming DD funds are still permitted. Seems the default is to allow two way DDs.