Tartarus Pro - D-pad and small round button stopped working

I am having an issue where suddenly the d-pad and small round button no longer function on my Tartarus Pro. All other buttons, including button 20, work fine. I've tried uninstalling Razer Synapse and Central, removing %PROGRAMDATA%/Razer, and reinstalling but this didn't help. I've reset my profile and the keybinds and rebound them, but that also doesn't help. I want to say I've been having this issue since around the time I upgraded in place from Windows 10 to Windows 11, but that could just be a coincidence. I'd think it might be a hardware failure, except it seems odd that I'd lose all four d-pad directions and the little thumb button next to it at the same time, and for no reason (no spills, no drops / things dropped on it, etc.) Does anyone have any ideas? I didn't expect this thing to have issues barely two years after I bought it...