The next image will show the problem I am having.
I've been playing around trying to fix this, I had this issue ages ago once but I never found a fix, a year later it has cropped up again. I have checked face orientation, normals are facing the correct way, there are no extra faces inbetween those sections, I have merged vertices by distance, applied rotation and scale, my seams and UV seem alright and I have no marked sharp edges. Images shown below, what have i missed?
Above is the blend file.