Yes and it seems Denon themselves recommend this, which is odd because all the ports are supposed to be to the same specification. It seems like they know their design is marginal and that there are units out there that don't quite meet spec. Most people will not notice because either they are still using 1080p or only 24fps, where they don't require anything like 18Gbps. If bypassing the AVR fixes it I would definitely pursue the problem with Denon.
As someone who had to do the same in 2016 with Yamaha and where a Yamaha supplied replacement ultimately fixed it, I can tell you it is certainly possible for the AVR to be the cause of such problems even when they are doing no video processing and are just passing through the signal.
LG OLED65E6V, Yamaha RX-A3060 AVR, Oppo UDP-203 UHD Blu-ray player, Apple TV 4K, Sky Q 2TB, Chromecast Ultra
Home-built Ivy Bridge i5-3570K HTPC, 8GB RAM and Nvidia GTX1050 GPU with Plex and Jriver Media Centre,
Ruipro 15M Fiber HDMI cable, B&W FPM speakers, Logitech Harmony Ultimate intelligent remote.