Hi,
I tried with 2 pictures from OneRS 4k action cam (Insta360) but seems these pictures are traited as fisheye 360 pictures. (Half picture mask is applied)
Results are always weired whatever Ptgui settings.
I also tried from a previous PTGUI version but still the same.
If you remove all Exif datas and then load them in PTGui with Action Cam settings this works well.
Here is 2 pictures if you want to play/check with them.