So I’ve had the same problem described here
Enter Network Password? but using my xbox one. I sorted it out on my laptop using the net use * /delete as suggested. But I can’t work out how to do that on my xbox.
These are shares that I had public, removed from public, set to full access on my admin account, but now I get asked for a username and password. however even giving this username and password (including the domain) doesn’t work.