I can add that the playhead (which is the name for the timeline cursor AKA the little green triangle) does not appear during playback in audacity 2.4.2 in bullseye. I'm running it on Wayland in Gnome, Linux kernel 5.10.4-1 (2020-12-31) x86_64.
To add more detail to the behaviour: the playhead should be visible when the timeline is clicked (even when not playing), but it is not. However, after playback is stopped or paused, the playhead -does- appear. Hints: This issue also appears in the audacity packaged for Ubuntu. https://bugs.launchpad.net/ubuntu/+source/audacity/+bug/1877833 speculates that it's a GTK3 issue. The official audacity site recommends building audacity from source with gtk2 against wxwidgets 3.1.3, rather than gtk3 against wxwidgets 3.0.0: https://www.audacityteam.org/download/source/ . -- "Believe those who are seeking the truth. Doubt those who find it." - Andre Gide Rob Teszka Magic <https://robteszkamagic.com/> | Facebook <http://facebook.com/robteszkamagic> | LinkedIn <https://facebook.com/robteszkamagic> | (604) 309-6993
