hAP ax S as device is in its infancy ... and so is wifi driver (wifi-mediatek). Unfortunately this means instability (we've seen the same when ax devices and ax drivers came through) ... and hopefully thigs will get better in upcoming ROS releases. So your only hope is to run development ROS (beta/RC) and see if things become better ... and by all means do provide feedback (in release-specific threads, such as V7.23rc [testing] is released!) which would give MT developers much needed information on what needs to be improved.