Upload speed approaching zero, outage detector tells me everything is fine.

So I had hoped this was just a small blip that would clear up on its own in a bit, but currently my upload speed is so low I am incapable of even talking on discord, much less conducting business from my home. From what I can see on my modem, there's no problem with the SNR, I'm not getting any bad packets or noise in the line, but even the smallest amount of upload, for example speaking through voice, appears to get choked into oblivion for reasons unknown.