external monitor not working after 10.15.6 (and 10.15.7) update

After 10.15.7 update, MBP mid-2018 and CalDigit T3 Plus lost the external display (Samsung TV). The cable was DisplayPort-HDMI. System has been working for two years previously.

(I tried to reset SMC, updated firmware of T3, installed some CalDigit drivers, but no help)

I talked to Kensington technical support yesterday. They suggested that I try an "Active" adapter and it worked!

I was using a VGA to DisplayPort adapter and it wasn't working. I switched to a DVI cable with an "Active" DVI to DisplayPort adapter and it works.

I have not upgraded to OS 10.15.7 yet, I'm still using 10.15.6.

I've been through a nightmare with this issue and I can't believe it came down to an adapter. Also hard to believe that with all of the calls to Apple Support, visit to Apple certified repair shop, Kensington support, etc., no body suggests this until yesterday.

Oh my goodness... I spent so much time trying to figure this out... I kept getting this flashing of the screen, as if the port was powering on and off. Very strange. Here's my work-around:

1) Make sure the monitors are powered off

2) Wake up or turn on your macbook

3) Turn the monitors on, starting with whatever one is primary

4) If that doesn't work, then turn off the monitors and turn them back on

I do hope they fix this in the next release! It's super annoying.

I have same problem. I use Vention adapter. All ports, not working after update to 10.15.7.

I have the same issue. I’m using a Kensington, SD2400T, dock.

Does anyone else have the same issue with a Kensington dock?

I tried the "Displaylink" fix and it did not get my HP monitor working again. I tried everything including booting to safe mode. That update just killed my second monitor.

I finally got mine to work after resetting my PRAM. However, I had to use the original keyboard because it would not response to 3rd party keyboards. I'm running an iMac Pro.