Thank you to those who have answered my question! I'm sure these answers might help other people with similar issues. I can't accept any of the provided answers because the problem somehow solved itself. I guess it was a software issue, but I don't remember if I did a firmware update since I've started having this issue. The right click seems to always work now, and I've done nothing to the mouse. Could've been an update to G Hub as well.
Thanks again! If the problem reoccurs, I'll try the fixes that were suggested!