AR9280 seems to be problematic, another older thread about it: http://forum.mikrotik.com/t/ar9280-low-speed/62030/1
I think it may be down to radio EEPROM contents, the ROS wireless implementation is rather specific to work just with Mikrotik hardware and it may need some extra data/fields in there.
Best would be to compare EEPROM dumps from radio that works and one that doesn’t using https://github.com/rsa9000/atheepmgr
Update:
I just checked rb711-5hn board that does have AR9280 radio on it and there is NO EEPROM connected to it at all. Maybe WLE200NX would run without it?
If you are feeling adventurous just shorting clock/data pins should make it unreadable…
Here is FCC report for WLE200NX including schematics: https://fcc.report/FCC-ID/TK4-10-WLE200NX