I was having the exact same problem! Reverting to a previous version of wordpress worked for me.
I’m running a version of Slider Revolution that came bundled with my theme, which is 6.2.6. It works fine on WordPress 5.4.2, but will break when WordPress is updated to 5.5.3.
On a site for another client, we’re running Slider Revolution 6.2.23, and that works fine with the latest version of WordPress.
So, I’d guess that if you either update your Slider Revolution plugin, or roll back your WordPress to 5.4, you should be able to get those toggles working again!