I have the similar issue on the below thread
I got a Macbook pro 2019 with i9 processor.
We just bought it about few week ago, the external screen will flickering when attach to my macbook pro.
I have tried
but also not work.
I have called Apple support, they replaced a new motherboard on the Macbook pro but still doesn't work, the problem still exist.
Anyone having the same issue too? That's make me so painful and annoying.