As other users in the forum, I tried to configure a RB Pi3B+ as an access point with no luck.
First I used the usb configured as stated in the documentation (label CONFIG, directory named network, file name with configuration inside); the file was copied in the system-connection folder but no access point showed.
So I manually edited the configuration file, using vi and also via nmcli console, but che connection did not start, showing the following: Error: Connection activation failed: No suitable device found for this connection.
If I change the wifi.mode to infrastructure or adhoc the connection goes up and work flawlessy.
Currently HassOS 1.13 uses NetworkManager 1.10.2, a very old release. Maybe updating it will solve the problem!