Just got a seemingly random UI glitch in Ardour - I loaded the LV2 plugin in a new track, and suddenly there are black boxes all over the screen. Mousing over some of these made them update so that they look as expected. However, most of them would not update at all, which made the synth pretty hard to use (at least for a beginner ).
Reopening the UI and re-instantiating the plugin did not make a difference, the problem only went away after restarting Ardour. The next launch appeared to work fine, so it seems like a transient issue.
I’m running Arch Linux, Vital 1.0.3, Ardour 6.5.4.