Increased noise when freewheeling/coasting

The noise when freewheeling/coasting has increased from the normal freehub clicking noise to a more "hard and unhealthy" noise. The resistance also seems to have increased so the crank/pedals spins along. Example in the videos:

Anyone experienced this?

The trainer is still covered by guarantee, but if there is an easy fix, I have no problem fixing it myself and saving the local bikeshop the trouble...

Thanks in advance!