I had this with Premiere Pro 15.x ... because MS OneDrive had re-configured all the 'user/documents' folders into itself, and PrPro couldn't write to them. Took me a while to get the dang OneDrive obliterated from my system so that at launch of Windows it didn't magically reappear and recreate the user folders within OneDrive's protections.
But I've seen other situations where Windows doesn't 'see' one version of the apps as being ... appropriate or something. And I've had to go in and figure out how to set permissions and such so that the app is fully functional. Say 2019 could upload/download sync with CC without issue, but 2020 ... couldn't.
So check where the folders are and what permissions they may or may not have.