Glitchy track DSP display after restoring A/B presets with VST3 plugins

Description:

When I restore an A/B preset on certain plugins, I get a glitchy display on the track DSP UI. Showing then hiding the parameter sliders fixes it. I’m using Renoise 3.4.1 on macOS Catalina.

Steps to reproduce look like this:

  • Load CHOWTapeModel VST3 (a free plugin, as an example. I have noted the same problem with other VST3s and AUs)
  • Save and restore an A/B preset

Expected results:

expected

Actual results:

actual

Confirmed on 3.4.1, Linux, CHOWTapeModel VST3.

This also happens on Windows 10 with some VST3’s.

I notice the thread title has been edited to say VST3 plugins, but I’m actually getting a similar issue with the AU version of CHOWTapeModel. It seems to happen with any plugin that uses boolean buttons or dropdowns on the native UI.

Note that clicking the “Show/hide the parameter sliders” button to show and then hide clears the glitch.

Have this on my macs sometimes, too. Yes, I think only with VST3s.