I don't know about the differences between AHRS 1.1 and 2.0, but I had a similar issue when I first added an AHRS board to my homebuilt Stratux in 2018. These instructions from Chris Young (Stratux developer) resolved my issue:
There are calibration values that are measured from the gyro when the unit is first started up. If the unit was moved during this first-start routine, it could potentially cause this issue. If you still have the chip that exhibited this problem, try plugging it in, setting it level, and then go to the "Settings" menu and "Calibrate Gyros". This is a different function from the "Reset/Level" function on the GPS/AHRS menu. I'd be curious to know if the unit calibrates correctly, if not then this is a new issue for us.
Note: Those instructions apply to the Stratux web interface (i.e., connect a device to the Stratux wifi, then open a browser and go to http://192.168.10.1), not anything to do with iFly.