Heatpress Help!

I have been trying at this for nearly a month and I can’t figure it out. Any help is awesome!

I have a roll to roll heat press and every time I put something through it leaves creases in all the material.

I can put things individually or together and I get the crease. I have put just blank transfer paper
Printed transfer paper
Tissue paper

And I have put it in all sorts of combinations.

Any help would be greatly appreciated!

Thanks