maybe you need to create a Custom setup, (as trivial as you like initially) and save it, and then select it as your default.
Next time you run MSFS, it will default to that saved SELECTED Custom profile, and you won’t get that message.
If you read the message, it’s actually telling you to do exactly this !!
Looks like exactly the same thing that happened when I used my “Non profile supported” MS Sidewinder 2 FF Joystick.
Now I have a profile defined, its fine …