Can't record to new track

I’m a basic user. Been using Audacity pretty much the same way for years, though. I.e.,

  • Create a new track A

  • Record background noise

  • Use track A as the Noise Profile in the Noise Reduction effect

  • Mute track A

  • Create new track B & record my stuff

  • Apply Noise Reduction to track B.

However, what’s different today when I started recording to track B is that the recording appends to track A. I can’t get Audacity to record to track B. Tried deinstalling, reinstalling, new file. I am using my Bose headphones (as usual) but notice that there’s only a Mono recording channel - no Stereo option, which is odd. I have External Microphone and External Headphones selected.

I’ve been using 2.4.2 for a while, no change. I’ve been on Catalina 10.15.6 since it was released. No change.
I do have a new Macbook (16" 2019). That’s the only material change I can think of.

Any suggestions/ideas?

Default behaviour of the Record button is now append-record.

If you want to change that to ‘record on a new track’ go to Recording Preferences and check “Record on a new track”.

Or hold the shift key while you click the record button, or do Shift+R to begin recording.

– Bill