Hi rgbtxus,
I have recently changed to a 10 Micron GM1000HPS and do not appear to have a problem with my time to meridian flip. I have been away from home for a few days (and am away this weekend) however, I will try to get into my obs tonight and check settings.
I know that the location setting in the handset will set your hemisphere and I had initial confusion setting the local time - UTC and Timezone offset and DST - due to the phrasing in the manual. I stupidly was setting UTC as my local time on the day (GMT+1hr for British Summer Time), then setting Timezone as +1 (becuase I was ahead 1 hour due to DST) and then ticking the daylight saving time option. I found the time on my handset was off by 2 hours and it took me a few attempts to get my setting correct! So, at the sake of driving you nuts, do a triple check of time. If you are slewing accurately, it displays correctly on the handset and tracking unguided well it must be set right (as you say).
There is a Mount Logger available on the 10 Micron site for download. Which 10 Micron firmware version are you running? I run 2.13.6 the current version for the 1000HPS (there are other beta versions available). I use Per's driver and it is straightforward to use.
I connect using an ethernet cable via router - your issue could be related to the wireless connection but I'm not sure. I have the wireless version too but have only used the ethernet cable. You could try posting on the 10 Micron forum for help too if you haven't already.
Happy to help if I can,
Barry