Comment 9 for bug 1909030

Sorry for the delay, Anyway, the device is able to use 44k1 without problems and because VLC works fine we can probably rule out jack, and pulse too. Studio-controls is just a script that runs jack and adds bridges to it using software that is not a part of studio-controls so it is not studio-controls specific. Really, that leaves discord either not liking 44k1 or not being able to deal with large buffer sizes. It would be interesting to know what discord asks for when it opens the audio device. You can check this by stopping jack in studio-controls, make sure vlc is not running, run discord and while discord is running run:
cd /tmp && wget https://community.ardour.org/files/adevices.sh && bash ./adevices.sh >adevices-pulse
Attach adevices-pulse here or look at it yourself. The lines to look at are:
used by: pulse
rate: 44100 (44100/1) - The 44100/1 means it really is 44100 as measured by the computer
period_size: 4096 - what we call buffer size, the amount of memory pulse can deal with per period
buffer_size: 8192 - buffer size X nperiods, the application deals with one half while the device deals with the other and then they switch when the device says so (at least in jack) pulse does other things sometimes.