Nothing new here, but just to confirm: I’m getting reports from Pro Tools users too (typically saying they can’t activate their plugin, and that’s because they (understandably) paste the serial number, which then gets pasted twice etc…).
So, for now, I tell my users to not use the keyboard shortcut to paste text in my plugin, but use one of these solutions (well, workarounds):
- paste the text using the context menu (mouse right-click -> Paste)
- paste the text using the Pro Tools menu bar: Edit -> Paste
And yes, this seems to be something specific to the interaction between Pro Tools and JUCE-based AAX plugins, as the keyboard shortcut works fine with the same GUI controls in the AU or VST2 version in various other hosts (Cubase, Live, …)
Edit: The version I used to reproduce this is Pro Tools 2020.9.1 on macOS Catalina.