Unload when extruder is hot

Hello,

I have some problems with my cr-10-s printer.
First when I want to print with a pre-heated extruder the printer starts to unload the filament.
Only way to overcome this to cool down, then the print comes out fine.
Second thing, I think it is related, is when I want to do a two color print, after the swap and the load of the filament, the print starts but before anything is printed, an unload is done. And this keeps on going.
As I sad I have a Creatily CR-10 s. Firmware is 1.8.3a. Slicer software is Cura or Prusa, but I don’t think it is a software problem.
I hope someone can help me.
Kind regards.
Joost Soontiens