I guess it's not a driver problem. This problem happened to me. This kind of problem may occur if you've edited monitor settings with CRU. If you don't use CRU, you can try editing for 144 hertz values with CRU. Note: CRU software may damage the monitor.
It is mentioned in the driver known issues section as a bug regarding Radeon Vii (but it seems to be the way amd mention bugs that they akwnoledge by marking only their flagman solution).
The issue looks to be pretty common for all amg gpu's:
RX 5700 XT memory clock stuck causing high temps when idle also had it on RX 590
But have to mention that i don't have the prolem when i connect the exact same 1440p 144hz monitor to vega 56 via the same connection (dp 1.2)
Still can't answer whether it's a hardware or the driver bug.
I try this Solution:
and work for my
I created a new resolution of 144 Hz in the CRU program with the LCD standard parameter, memory clock speed decreased to 300Mhz
It's a bug! How do you explain the custom 143hz then ? It's working in my case if i use that refresh rate. The clock speed decreses when i'm on my desktop as it should.