4K display randomly uses 30Hz instead of 60Hz

I'm using an Dell P2715Q 4K external display with my MacBook Pro (Mid 2018) and a StarTech USB-C to DisplayPort adapter cable (CDP2DPMM6B). Sometimes when my mac wakes from sleep it is using 30Hz instead of 60Hz.

In order to fix it I have to turn off the monitor, unplug the USB-C cable, plug it back to a different port and turn the monitor back on, and I usually need to repeat these steps a couple of times. Or just unplug and plug the cable in the same USB-C port for 3 or 5 times. This also seems to be completely random

I had none of these issues with my previous MacBook Pro (Early 2015), a DisplayPort to Mini DisplayPort cable and the same Dell screen. Always 60Hz.

Is there a permanent solution for this? Having to spend a couple of minutes with this roughly every 3rd time when my Mac wakes from sleep is extremely annoying.

(yes I have cloned parts of this closed and unanswered post)