Recording problem with Cubase AI

A week ago I bought the Recording Pack UR22C ncluding Cubase AI. The first few days everything just worked fine. Then I took a break for two days, now the audio files are not recording anything anymore. Even thought the interface with headphones etc. seems to work just fine. I can see the audio signal from my microphone reacting in the display before recording. When I press record, nothing is being recorded. Can anyone help me??
Thomas

Hi and welcome on the forum,

Hard to guess, sorry. Maybe a video would help.