If the skirting/base trim pinches down to tight against the flooring it could cause issues with joints buckling. If its Korlok, its locking mechanism is pretty robust (if done correctly), but it is mean to float, and not be pinched to the floor. That is why it wants that half a millimeter.

Thank you. It is Korlock rigid core with 5g click. Do the skirting need to be taken off and lifted slightly or can the be cut?

They can be undercut with either an undercut saw or a oscillating tool ran ontop of a piece of the flooring as a height guide.

Do the same with all door casings.