If your IP Ranges in Wifi and wired are the same, look into your router setup. Mostly it is a setting called AP Isolate or Client Isolation that prevents communication betwen Wifi Devices
#Ethernet is ok, but not via wifi
radiant anvil
How did you flash MainsailOS ? Using RPI-Imager?
If yes, it mostly had issues if SSID is hidden ( for unkown reason), but thats something you have to google from Raspberry Foundation Docs. MainsailOS is currently an Raspberry Pi OS legacy enhanced with "Klipperversum"