18 Area-51 AA18250, U4025QW Thunderbolt, no 5120x2160 120 Hz

I am facing problems connecting the U4025QW Thunderbolt display to an 18 Area-51 AA18250. Using the TB4 cable, that came with the monitor, I receive a "no signal" message along with an unresponsive notebook when trying to use the full resolution of 5120x2160 120 Hz. It works fine with 60 Hz. I can only achieve 120 Hz by using a separate USB-C to DP cable and routing the USB uplink through another USB-C to USB-C cable. I tried using another TB4 cable with no luck. In addition I tried to factory reset both the display and the notebook, updating drivers. The displays firmware is updated to the latest version (104). The notebook has all updates installed including the latest firmware.

5120x2160 120 Hz is working just fine with my other Alienware m18 R1 and another HP laptop using the same cable.

Is anyone using the same combination (18 Area-51 AA18250 or 16 + Dell U4025QW)? There is either a bug/defect in the Thunderbolt implementation or I have received a defective unit.

Thanks!