When using the ASIAir with my TTS Panther Alt-Az mount (Meade ETX90/105/125/LXD75 Emulation) the mount tracks well until I cross the Meridian. At that point the corrections appear correct in phdlogview, but the error continues to increase on a straight line trajectory. Because this is an alt-az mount, I have meridian flip disabled.
See attached PHD2 log at the 20:48 time index.