Very slow upload speeds. Download speed is normal. No equipment changes

Hello, 

Last week my upload speeds dropped to around 0.5 - 2mbps. Download speeds are still normal (400 - 500 Mbps).

No equipment changes. Connection has been working normally 6+ years prior to that. 

Modem: Arris SB6183 plugged in directly to the PC

Unplugged, restarted, new cables etc. Nothing has helped so far.

Any suggestions how to fix?

testmy.net result: https://testmy.net/db/i~g3nG8f4.GXPQowtGP

Arris status: