EddyQ

I recently photographed the milkyway with very good results in Affinity Photo.
 
The stacking alignment failed as it often does with photoshop and for good reasons.
Turns out, the stars do not move the same amounts.  So, even if you manually align in the center, the average stack will have fuzzy stars outside the center.
 
The best approach (IMO) is demonstrated by Ian with PS: https://www.youtube.com/watch?v=zzVSm64zq44
This same process can be done with Affinity photo.  Works great at noise reduction and produces much sharper stars and details.

Perhaps this is a different issue, but my 8 photos of the milkyway fail to align properly.  They are 20 second exposures taken in succession on a good tripod. The only movement are the stars as the earth rotates slightly.  Most of the photo is the sky, but I do have the ground at the very bottom (which does not move).  Is there a way to mask out the ground objects before align and stack?  I am assuming these objects moving differently than the stars are causing the algorithm issues.
 
After importing the photos and stacking, I have tried to add masks to each individual photo layer.  That did not change anything.
 
Any thoughts?