Adobe Reader doesn't work, when assigned as default pdf reader

Adobe Reader is the default pdf reader on my Windows 10 PC. I realized that it only works properly when I start Acrobat Reader application first (which opens the GUI), and then I click on the actual pdf file to open.

But if Acrobat Reader is not already running, it won't open when I click on a pdf file. I can see it running in task manager, but the actual GUI never opens.  After this, even if I try to open the app by cliccking onj it, it just adds another process to the task manager, but won't open.

The only way to make it work is to kill all Adobe Reader tasks and click on the app to start an empty GUI, and then open the pdf files, when the app is already running.

Why is this happening? I've reistalled it, cleared the cache, deleted all Adobe related folders, etc, so don't  suggest "reinstall the app" since that won't work. Everything is the latest and updated.