13.3.1 breaks external DisplayPort monitor support for my dock

I have a 2021 16" MacBook Pro. Up through MacOS 13.3 I used a Dell D6000 USB-C dock to power my keyboard, mouse, speakers, camera, and 3 external monitors: 1 via HDMI, and 2 via DisplayPort to DVI adapters.

After upgrading to MacOS 13.3.1 the DisplayPort connected monitors don't work. They are not recognized in Settings->Display, nor are they found in the System Report USB tab where they appeared before. They work when connected to individual USB-C to DVI dongles (skipping DisplayPort), but not the dock.

I have tried all combinations of resetting the dock, MacBook, and monitors. I am convinced that the update broke something related to DisplayPort external monitors connected to older docks. Earlier this year, an update broke my using a 2011 iMac as an external monitor connected to a dock (via raw DisplayPort, not Thunderbolt).

Has anyone else noticed this and fixed it?