[altphil]

Edit: Possible WORKAROUND for some of you below in the update.

Ditto.

Dug in a little bit this morning.

First, the laptop screen works fine.
The 1st monitor creates a desktop, windows can exist on it, you can see the mouse, but you can't see anything because the 2nd monitor's desktop is displayed (mirrored) on the 1st monitor.
The 2nd monitor seems to work fine, besides mirroring it's display over the first monitor.

It's like the windowserver runs totally normal except it mirrors monitor #2's display on both monitor 1 and 2. You have this whole invisible desktop that should be on monitor 1.

The new displaylink manager app works great, as expected. But the "no rotation" thing makes it useless for my work station, which only fits on the desk with one monitor rotated.

It's certainly an issue. Going to suck at work until either the displaylinkmanager app can rotate or 10.15.6 is fixed with a new driver, I guess?


Update: (Workaround found for my case)
On my startech usb-c hub (DK30CH2DPPD), if I use the two Display ports output, I get the above issue. If I use one Display port for one monitor, and the one HDMI output for the other, it works totally like normal.
So it appears to be when you are using the first two outputs on the USB-C hub, you get the weird mirror effect.

I have it working now. Of course, now I have to go find an HDMI to DVI converter as I borrowed this one to test.

So there's a workaround. Sort of. If you can use different outputs, it seems to work. Apparently you can't use two of the same output types?