Need some help, keep getting banding on leatherette.

https://imgur.com/a/w1hKV81

I'm losing my damn mind over here. I ordered 10 sheets of this and I've already wasted 8. each time I think I've figured it out, but no. And it's always so close to the end.

I'm on a Wecreat Vision 20w, I'm at 50 power and 400mm/s. The finished images are around 9.5x14.8. Definitely getting to the outside of my working area, but has typically been acceptable. I've played with 300dpi, 200dpi, 250dpi. I've done power 20, and speed 200, I've done numerous different variations, tried different algorithms. I then cleaned the lens, cleaned the "nozzle". I regreased it.

Is it heat? I know it's not lifting because I've been laying it flat on a cricut mat to keep it secured. But it always as you can see, does this right towards the end.