I had the same problem a week or two ago. Everything has been working fine for almost 1 year, then one day the D5 NEXT RGB didn't start with the PC. Pump was working fine, RGBpx just wasn't working. I tried different cables, rebooting, full power off, no success. Then 24 hours later it started working again, no explanation. I contacted support when it first failed, but since it started working again I had to suggest I'd keep an eye on it and let them know if it happened again.

I'm also curious. Der8auer (see his youtube channel) produced a kit to achieve similar offset, but there seems to have been mixed results/reviews on reddit. It probably has more effect for hotter 39XX chips.

Hi since installing X.18 my D5 Next display seems to insist on Medium brightness, regardless of setting. Edit: The Kryos Vision display is now intermittently Max and Medium...