I can't reproduce the issue on my ArcGIS Pro 2.9.0.
In my case, the functions works as it should.
Reverse Symbol Order: Reverses only the symbology of the classes.
Reverse Values: Reverses only the order of the classes values
Have you tried rebooting the system and executing the activity on a new ArcGIS Pro project?
If the issue persists, try adding a few screenshots. Also mention the parameters used in the symbology.
Think Location