30 FPS, while monitor receives a 60Hz information

[Anatharias]

Hello, I've sent this request to the technical support 8 days ago and I'm still waiting for a reply, so here's the detail of my support request:

I got the latest Mac driver 1.10.2 on Sonoma 14.5 (M2 Pro MBP) with a Targus 180 Docking station.

My monitor is an Alienware AW3821DW connected through HDMI. That monitor supports up to 85Hz,**VRR and HDR, while connected through HDMI on that very Mac.

Though the Displays preference panel indicates 60 Hz, the monitor indicates 60 Hz, the UFO framerate test indicates 60 Hz, the test however leaves no doubt as to what the frequency really is : 30 Hz

Odd is that I sometimes get 60fps, but I'm in no way capable of reproducing it.
If I select 85Hz in the Preferences Panel, the display goes black and blinks an image once every 15-ish seconds.

The 30FPS situation is quite annoying as the whole system is slowed down whenever something needs to be rendered as a moving image, like a window scrolling, a YT video
When I get the 60FPS, none of that happens...

Attached is the debug files that the displaylink utility generates

DisplayLinkInfo_Output_20240611_163555 = issue is present, 30FPS on a 60 Hz resolution
DisplayLinkInfo_Output_20240611_150910 = issue is no longer present, 60 FPS on 60 Hz, just after closing the lid.

Unfortunately, opening and closing the lid doesn't always solve the issue.

thanks