Check your mount without ASIAIR.
Use its hand controller to GOTO a star (or coordinate) that is just to the east of the Meridian for a star on the hemisphere the Zenith is at. A star is easier to visualize, but any coordinate would do.
Use the GOTO command to move to that coordinate (do not slew -- use the GOTO -- since that should also turn tracking on with pretty much every mount).
Now wait for the star to transit just past the Meridian. This happens at exactly when the Local Sidereal time is equal to the Right Ascension of the star. At this point in time, issue another GOTO.
The second GOTO should cause your mount to perform Meridian Flip. There are a few mounts (e.g., the old Avalon StarGO) that does not have a Meridian Flip function; if so ASIAIR will not Meridian flip either -- ASIAIR uses the Meridian Flip in the mount.
If this second GOTO does not perform a Meridian Flip, you need to fix the problem. It is completely independent of the ASIAIR.
If the above works, then you need to make sure the ASIAIR and the mount maintains the correct times. The Local Sidereal Times must agree. Since you cannot check LST in ASIAIR, you can equivalently check UTC and Longitude. If your mount has GPS, be sure to turn it off and let the ASIAIR push the UTC and Longitude values from the tablet to the mount.
By the way, the level in mounts are very rough. Use a long bubble level, or a digital inclinometer. Tell the mount to move the hour angle to zero, and turn off tracking, and set the declination to your latitude -- i.e., the OTA should now point to Zenith. Now, use the bubble level along the side of the OTA to check if the OTA is perfectly perpendicular.