Hi @stark, welcome to the Supernotes Community!
Depending on your browser set up, naturally some hotkeys won’t work in the Supernotes Web App as they are conflicting / overridden. We’ve tried our best to reduce any conflicts but everyone has different setups. We’re looking into adding customisable keyboard shortcuts in a future update and have added your +1 for this. I’m moving this into Community Support as it’s an upstream issue.
In the meantime, we recommend installing the Linux Desktop App for the best experience.