Hi Steve, thanks a ton for the response, I appreciate it.
Regarding the sound, I didn’t even have the option of “default.” All I had were the HDMI options. I decided to install alsa-plugins-pulseaudio, and that seems to have done the trick (actually I went all out: alsa-plugins-pulseaudio, paman, paprefs, and pulseeffects). Now I can set the audio to default and all plays ok. I’ll start a new topic if it becomes an issue again, but I think it’ll be ok from here on out.
Regarding the “size” issue - when I load audacity, it looks like the DPI increased by like 300%. Literally every part of the Audacity UI is large - the buttons, the menus, everything. Thinking of it as a DPI issue, I dug around a bit more, and it appears (?) to be a HiDPI scaling issue, much like as shown in the screenshot of https://wiki.audacityteam.org/wiki/Linux_HiDPI_Support
I think the post on this forum, https://forum.audacityteam.org/t/force-audacity-to-scale-to-high-dpi-screens-ubuntu/42200/1 (Re: Force Audacity to scale to High DPI screens (*ubuntu)), speaks to this matter.
It’s so strange because I swear I didn’t have this issue before the Fedora 30 → 31 upgrade… Has any thing changed since the date of the above post - are there any other methods I could try - or should I still try to follow those instructions to see if that fixes it?
Thanks very much!