How do I reinstall the latest version of Photoshop?

I have had so many issues, bugs, glitches and random problems with Photoshop since I started using Adobe Cloud, I don't know where to begin. I am running macOS Catalina 10.15.5, on a 27" iMac, Retina 5K 2019. Every day, some new problem pops up and I end up moving the work to my old back-up iMac running Adobe CS5. Never had a problem with CS5... bullet-proof.

Anyway, how do re-install the latest CC Photoshop?

Thanks, in advance, to all who can help.