Similar with me, but Kubuntu. Installed Steam and started downloading some games, and the whole system became almost unusable until it had finished. Also I put some music on (YouTube), and the audio was slightly slowing down and speeding up.
I have used Linux for decades for servers, and I really want to move to Desktop Linux, but at least once a year I try and there is some major issue that stops me.
Seems that they're not accepting pull-requests via GitHub, which is a bit of shame.