Why won't Mac allow me to grant accessibility permissions to my Huion tablet?

Upon upgrading to macOS Catalina, it had told me my Huion art tablet, which was working fine for a year before I upgraded, was malware for some reason (even though they're a trusted, top named brand) and refused since to cooperate with it. While I can use it, it won't allow the tablet to properly work, such as making it register input too quickly (messing up smooth lines) and won't register pen pressure (something it had done before the upgrade).

On June 12th, 2020, Huion came out with a new driver for my version of the tablet, and I thought possibly I could finally have the two work again and followed the instructions Huion had given to install the new driver. However, my Mac is once again refusing to acknowledge it even exists, and when I go to grant Accessibility permissions in Security & Privacy, it will not allow me to even check mark it as seen in this video: https://youtu.be/WRqva5iqQhk.

I am at my wits end with Catalina being so restricting as I desperately need pen pressure if I want to make decent looking art. Any help would be greatly appreciated as I really, really need my Mac to cooperate with my tablet. If there's any way I could downgrade back to my old version of Mac, High Sierra, I may appreciate that even more.