MSI Afterburner voltage curve not working on Radeon 7800XT

I installed MSI Afterburner 4.6.6 in order to undervolt my Radeon 7800XT, but the voltage curve editor doesn't seem to be working properly. Instead of a single curve that I can edit the various voltages and frequencies, it shows two lines with no editing possibilities like shown in this picture.

https://ibb.co/cS9q8ZNH

Does anyone know of how this can be fixed to properly show the voltage curve for my 7800XT?

Thanks for any help!