Can't record bass guitar in GarageBand after OS upgrade

Hi. I've recorded a lot of tracks before using the same setup (GarageBand + Scarlett Solo + external headphones), then all of a sudden after macOS and GarageBand update, it stops recording my instrument. I can't even hear it when in monitor mode. I've googled and tried various solutions, but nothing has worked so far. I can see that the Scarlett is reacting to my play, so it's unlikely to be a hardware issue. My input device is set to Scarlett Solo and output to external headphones, but of course, I've tried adjusting these settings without any luck. Any ideas?