I assume you are in Track mode.
If you have polar alignment error, track mode does not follow stars that well in Explorestars. The 2/3 star alignment only corrects dec dynamically in point mode. Track mode just runs ra along at sidereal rate.
If you use point mode the stars will stay put but you will observe a blob because the point mode only adjusts telescope pointing 5 times per second. Also the fov will rotate some during exposures if the pa is off. For short ones that won’t matter as much as the little bumps five times per second.
Explorestars is not really the platform you want for astrophotography although it can be used if you do a few things:
1. Get a good polar alignment
2. Use st-4 guiding
3. Ensure you are in Track mode
Note that unless you have a self contained guider, you are going to need a laptop to run PHD for guiding. At that point you may as well go serial ascom.
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired