Remove the bike from the trainer.
Inspect and clean the quick release skewer and it’s contact surfaces with the bike frame/dropouts.
Reinstall the skewer and make certain it is properly torqued.
Clean the outside of the quick release skewer and the inside of the trainer at the skewer support cups.
Reinstall the bike into the trainer with proper clamp compression and retest.
Essentially, make sure every contacting part from the bike to the skewer to the trainer are totally clean and properly installed.