open with ... causes one program to appear multiple times

I have a: fresh installation of Linux mint 20 cinnamon a week ago (luv it) and i have 3d ays ago installed okular for pdfs. *My Problem:* when i want to open a file, that is unknown to the system with open with... then i get the weird behavior of many okular's to choose from. Please see picture below: I installed okular from the standard 'Software Manager' it is version 4:19.12.3-2ubuntu1. Found out it is a KDE Graphic Module. And I looked up odd behavior of open with... *My question*: How can I only show one okular in the choose Program tray of open with... ? *I want*: > Okular to appear only once in the "Open with..."- list. I think the okular options are getting more (kind of funny).
Thanks in advance