I’m a long time Audacity user using a 2012 MacBook Pro I7 Intel 2.3 Ghz processor with 16 GB Ram running MacOS Mojave 10.14.6.
Starting with audacity 3.1.0 and so far through 3.1.2 and an 3.2.0 beta build I just built, the recording/playback cursor is very noticeably jerky. Please note the jerk is the same on recording or playback. Version 3.0.5 does not exhibit this condition, though there is a very very slight jerk that isn’t noticeable unless you are looking for it. At the normal edit/recording zoom of CMD-2 it seems to jerk every ½ second or so. I see it even at zero zoom, Cmd-F, but not so evident. It seem like a buffer swapping/filling issue just off hand.