Tech@ZWO
Thanks for your response. Maybe, the function is already included, but it doesn't work.
Did a cross-check with my gathered data. Stargazing-Livestack, individual fits. After the fifth frame, you can see a change in the recorded RA/Dec coordinates in the fits-header. Then, this value is kept constantly until end of capture (no matter of 100 or 600 frames). However, you can clearly see the dithering and shift/drift over the whole sequence. Conclusion, if they do a platesolve, this happens only once (after or around the fifth frame), or, they do not record it in the subsequent files. And I cannot see any re-centering. Therefore, stars close to the edges move off the frame and get lost for identification as reference stars, likely leading to a "stacked failed".
Please take closer look on it. If necessary I can provide more data.
I checked with my gathered data from February until December. Therefore, it is not related to any update or firmware release.
I'm pretty sure and confident, that a proper and periodically platesolve and re-centering can significantly improve the Stargazing experience.