I have been having this issue ever since since the late 2018, but I have been using a work around by opening up existing files and renaming them.
To put it simply: I open an app, try to create a new document, the new document window appears briefly then vanishes. This will repeat everytime I would make this attempt.
I've been scaning the web for a solution earlier, but no one seemed to be posting the issue and every fix did not correct the issue. This most recent scanning shows the issue being address by checking CreativeCloud sync, but now it has been updated with no luck and I'm having diffculties find a solution.