I have become aware of something that seems to be more and more common. It seems that some DAWs don’t read the entire plugin file when loading it - they open a previously saved “cached” version of the plugin if the DAW has “seen” that plugin before. They likely do this to speed up loading time.
I was tripped up by this several times when developing my plugins - first noticed in Cakewalk - but now other DAWs seem to be doing this too. Sometimes when I save a DAW project with a plugin loaded in it that plugin will not update to the latest version until I re-scan the plugins in the DAW’s plugin manager. In other words, the project sometimes opens with an old version of the plugin (old UI, etc.) even though a newer version of the plugin has been saved to the plugins folder.
I have now made it a habit to delete the “installedAAXplugins” folder in Pro Tools and re-scan the plugins folders in other DAWs when testing new plugin builds to ensure the DAW reads the latest version.
I believe this only causes problems with rebuilds of the same plugin version (i.e., during development) but just thought I’d mention it here, FYI, as it caused me much confusion until I understood what was happening.