I recently had this issue pop up as well. Ive been imaging NGC 6888 for several days in a row since June 27th. The first 3 days the auto run sequence went off without a hitch. Nights 4,5 and 6 have had issues after the Meridian flip. Images are streaked as if no tracking.
Looking at the log, the only notable difference I see is guide did not settle and timed out.
I'm on a semi permanent setup. Nothing changed with the rig during this time. Only thing noteworthy is I used a new Android device on day 3. I normally run from my iPad. Days 4 onward I was back to my iPad, and thats when I see issues. I feel something got changed in the guiding settings, but it all looks right.
Sky-Watcher CQ350
ASAair MINI
(abnormal session on the left, normal on the right)