Tech@ZWO
When I went into the ASIAIR report log in About > Bug report, it did not accept the Meridian flip option selection , I was able to go further only by selecting "Other" option. So, it may be under "Other" instead. This failure occurred in three consecutive nights (all in the -4 degree C range). But afterwards, while indoors, the meridian flip executed flawlessly.
I will try it again when we get similar weather conditions..