18 Area-51 AA18250, AW3418DW, USB-C to DP, not seen on boot

I have trouble finding a reliable USB-C to DisplayPort cable. Using a goobay wired cable, got very bad flickering due to interference. I switched to a fibre optic cable, which solved the interference problem; however, the external monitor (Dell AW3418DW @ 3340 x 1440,  120Hz) with DP 1.2 was not recognised at boot. The only fix is to unplug the monitor and plug back in again. It is connected to the Thunderbolt 5 port on the Alienware 18 Area-51 AA18250 laptop (Windows 11 24H2). Wondered if anyone could recommend a, preferably wired, USB-C to DisplayPort cable which would not cause these problems?

Btw. Dell support did not recommend using an adaptor, and said to use a cable instead.