Can't get 4k@60hz out of my M2 Mac Studio's HDMI port

[retrocool]

I'm trying to connect a Benq BL2711U to a Mac Studio M2 using its built-in HDMI port..
I've tried three HDMI cables, of gradually increasing cost and now have a Betron 8k 2.1 48Gbs cable.
All of them max out at 30Hz, using 2560x1440 HiDPI. I can choose 25Hz or 30Hz but nothing higher.
The monitor works fine at 60Hz via a USB-C to Displayport adaptor, but I want to use the HDMI port.
Any ideas? Is it the monitor, or a software or hardware issue? I think I ruled out a cable issue by using three different ones, two of which claimed 4K@60Hz capability, and the latest cable claiming 8k@60Hz.
TIA

 

[Cadarnfel]

according to Display Specifications there is a HDMI 1.4 port and a HDMI 2.0 port. Are you connecting to the 2. port?

 

[Fishrrman]

I looked up the specs on that display and it has TWO HDMI ports, is that correct?
The specs said that one of the HDMI ports was "HDMI 1.4", and that the other one was "HDMI 2.0".

Which HDMI port are you using?

One other thought...
If nothing works (using HDMI), but you CAN get 60hz via the displayport, well... sometimes one has to do, what one "has to do"...

 

[retrocool]

That was the right answer! It seems one of the HDMI ports on that display model is gimped for some reason. Thanks for working this out, it really had me stumped! I had seen the specs say "HDMI 1.4 / 2.0", but I just assumed it meant it supported both standards. I definitely should have tried the other port.