PMTeam@ZWO
I opened the same image I sent you in Siril and chose the same star as you and got different results. Firstly, how can this be? Secondly, how can you tell from that data that the star is not round? If you zoom in to that star it is perfectly round even at high magnification. Again I cannot upload my screenshot to show you my siril pic. It is only 2.3Mb so it should be good but something is preventing me from uploading anything so please take a look at my settings to see if something is wrong. Also i will email you my screenshot so you can see its the same star but different values. let me know how you go.
many thanks again
Nick