Torch snags on material

[Wolpen]

Good day,
when torch moves along material during cutting, it snags on and doesn't maintain correct distance from cutted material.
What can be a reason behind this situation?

[JAZZCNC]

Good day,
when torch moves along material during cutting, it snags on and doesn't maintain correct distance from cutted material.
What can be a reason behind this situation?

The material is most likely lifting due to heat distortion. How thick is the material.?

If you are cutting this material say less than 3mm and even up to 5mm will do this on some material, then you really need THC so the torch is lifted when the material moves.