T580 suddenly doesn't charge battery (Windows 10)

Something just happened to my T580 -- neither battery seems able to charge. The battery indicator on Windows says "plugged in" but does not say "charging"

With the swappable battery installed, the charging LED on the left edge of the laptop does not light up. Removing that battery, I now get a white LED there, but it seems the internal battery isn't charging either.

This occurred suddenly, seemingly after a Windows 10 update on 01/15/2025 ,but I'm not sure if that's related.

Uninstalling the battery and AC adapter from Windows didn't solve it.

I did find this on the Lenovo forum but haven't tried the whole thing: https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T-series-Laptops/T580-2nd-battery-does-not-charge-stays-at-45-under-Win10/m-p/4212022?page=1#4212082