Option keys stopped working

I have a non-Apple keyboard that I've used for 3 years with my Mac Mini M1 2020. A few days ago, both Option keys became unresponsive. I don't think I've changed anything at all, nor did any updates during this time. I did just update to Sonoma 14.0 today, and unplugged then reset my keyboard, and the problem persists. I use the Option key daily for work for typing, text jumping, and in Excel and am hoping there's a quick fix. I saw that someone asked this question in 2020 also, which made me think this is a software issue rather than hardware.

When the Mac's "Keyboard Viewer" is up, all keys appear responsive except for the Option and Function key. I'm not sure if the Function key has always been that way because I never or rarely use it. But Control and Command show up fine. Because it is a keyboard with the Windows layout, I do flip the position of the Command and Option keys in System Settings -> Keyboard -> Keyboard Shortcuts -> Modifier Keys to make it like a Mac layout. But it's been working fine that way for years, and upon checking that the settings are still the same. Any help here is greatly appreciated, thanks.