it seems that I have the same issue.
I am also running Manjaro, version 18.0.4, i3 window manager, Linux kernel 4.19.66-1-MANJARO, with Audacity 2.3.2 installed from the default package repositories. I also use pulseaudio.
The symptoms Sargas described in the initial post are the exact same ones that I experience.
The way pulseaudio is started on my system is via systemd in user mode, which should be the default on arch based systems according to the arch wiki.
Some things I noticed:
When I record something, it seems to be a sped up version of what I was saying, because if I play it back via Audacity with Playback Speed 0.08 or so, it sounds almost normal.
Also, recording only worked just after I installed Audacity. Now when I start it, it only “works” for half a second or if I mash the record button and the recorded sound is either still the strange, sped up version or nothing at all.
If I try to export these recordings, it only becomes static.
I tried starting Audacity from the command line, to see if I got any output, I don’t know if it is unusual or might help but I get a whole lot of:
ALSA lib pcm.c:8432:(snd_pcm_recover) underrun occurred
And when I try to record anything:
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: 3881
Expression 'PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 4253
I’ve also cranked up the log level of PA and made a pastebin of journalctl after clicking on the record button in Audacity, if that helps.
If there is anymore I can provide, I’m happy to help and also for any help provided.