10.15.6, external display problem

I just discovered this thread. There is another thread about the same topic, but this seems more active.

I'll state my problem:

Hardware:

MacBook Pro 16"

• 2,4 GHz 8-Core Intel Core i9
• 64 GB 2667MHz DDR4
• AMD Radeon Pro 5500M 8 GB
• 4Tb SSD

All external Displays I tried this with (all result in the same Problem):

• AOC Q27P1
• Lenovo LT2452pwC
• HP EliteDisplay E242 Monitor
• Dell U2412M
• Dell 1907FP

Adaptor I have this problem with:

Belkin USB-C to VGA adaptor (F2CU037)

This Problem immediately occurred after the update to macOS 10.15.6. I had a display connected right before the update (it was working perfectly) and right after the update (that's when the problem first occurred).

This is a very strong correlation for me. The adaptor works fine with a surface book and all the above mentioned displays, which leads to the conclusion that the problem lies with the macOS update.

When I plug in a Monitor via the adaptor all connected displays and the internal display start to flicker as if they can't properly be detected. This goes into an infinity loop with a flickering pattern (internal display lights up for 1/10 of a second and goes black for 1 second).

I have tried everything mentioned in this thread including rebooting in safe mode, resetting NVRAM and PRAM, etc.

The update to 10.15.7 did not solve the problem.

Of corse I can just buy a new adaptor that supports DP or HDMI (my Belkin HDMI adaptor works just fine) but I think we all agree that this is not acceptable if I spend 6k for a laptop. I have to rely on this adaptor for presentations if there isn't a HDMI available for the projector. So I bought the apple adaptor. But no one can seriously suggest that this is a solution.

Addressing the comments that the adaptor wasn't supporting high speed transmission or a certain resolution or isn't certified. Sorry but this is nonsense. First of all this adaptor worked perfectly fine previous to the update. Second Belkin is a premium brand that supports all standards. Especially with VGA its not a problem of any speed restrictions. With 4k this might be a different story but not VGA.

I will go to an apple store next week, let's see what they have to say. I am really disappointed with apple on this one. I just expect not to bother with something like this.