This is a big issue for LG. Monitor that is useless next to a router??? I'm not a fan of Apple's overpriced products, but I don't think this would happen if he purchased Apple Display...

This monitor is described as an 'Ultrafine 5K monitor' but the resolution is printed as 2K in the article? Is this a typo, Hilbert?

well my guess seems there is issue with hardware shielding ... seems especially on the thunderbolt port or cable its pretty basic in electronics, as the higher data-rate goes bigger, its also become more sensitive to noise... 1080p said using 1.485Gbps, while hdmi 2.0 up to 6Gbps not sure how high thunderbolt can, but plain calculation if 5k is 5x 1.4Gbps then its 7Gbps

You are thinking individual channel bandwidth (HDMI has 3). The first HDMI version can support up to 5Gbps worth of video/audio data and 1.3/1.4 can support up to 10.2Gbps. Version 2 supports up to 18Gbps and 2.1 supposedly 48Gbps. 1080p@60hz 32-bit color needs 4Gbps. 4k@60hz 32-bit color needs 18Gbps. 5k@60hz 32-bit color needs 22Gbps. Thunderbolt version 1 and 2 provide 20Gbps but the only difference is how they split that bandwidth (version 1 between 2x10Gbps channels and version 2 with 20x1Gbps channels). Version 3 is supposedly be able to provide 40Gbps. Here's a good calculator for video bandwidth: Digital Bandwidth Calculator