Whilst I have never experienced your issue exactly I can say that the Sonnox Fraunhofer Pro Codec can exhibit some weirdness on my XP system if … once it’s loaded … it is loaded again but with a different preset.
The workaround is to save a preset ‘no insert’ … a preset with no inserts obviously … and load that ‘between’ the two desired presets.
Then load the desired new preset.
Works 100% of the time.
I strongly suspect this is something to do with the plugin … maybe a dongle call issue or something like that … rather than WL. It only begin to emerge as an issue after a version update.
Good luck.
Hope this helps.