Some folks are suggesting ferrite beads, others are suggesting shorter cables.

If one has a medium-sized chunk of money to burn, one could try fiber optic cabling. I've personally had -AFAICT- perfect results from Monoprice's "SlimRun AV" fiber DisplayPort cables, and Nippon Labs' fiber HDMI cables. [0] I expect that Monoprice's fiber HDMI cables and Nippon Labs' fiber DisplayPort cables are also fine, but I've never used those, so I cannot comment.

For folks concerned about "dreadfully fragile" fiber optic cables, I do know that the Monoprice cables are durable... a vigorous misadventure caused me to torque the hell out of the monitor-side connector. The connector bent, forcing the case split a bit at the seam. After some counter-bending of the connector and pushing its case back mostly closed, the cable works fine. Given the outward similarity in build quality, I expect that the Nippon Labs cable I have is at least as durable.

[0] Both families of cables drive my "4k" HDR monitor at 60Hz without lossy compression.