Audacity only creates another empty track when i hit record

for context:
Audacity version 2.2.1 (Ubuntu Bionic Official Release)
Ubuntu 18.04 LTS, XFCE desktop

I’m trying to make use of the overdubbing, and wish to record a second track below a first pre-recorded track. i hit the record button, record some test audio, and then stop the recording. when i hit the record button again, a new track does appear - Audacity dosen’t record anything to it though. i had trouble finding an issue like this in the forum, so let me know if it’s a duplicate!

when running through the terminal, i see this message appear consistently when i attempt to record additional tracks:

Expression 'err' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 3355
Expression 'ContinuePoll( self, StreamDirection_In, &pollTimeout, &pollCapture )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 3896
Expression 'PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 4274

all help appreciated! thanks in advance

What are you recording from?
What are your settings in the device toolbar?
Ensure that “Software Playthrough” (in the Transport menu) is off (not selected)