LG UltraFine 5K Display possibly affected by interference from nearby wi-fi router

A Wi-Fi-related issue with some LG UltraFine 5K Displays has possibly been discovered, one that effectively renders the high-resolution Thunderbolt 3 displays unusable if an afflicted unit is positioned within a few feet of a router or a wireless access point.

The LG UltraFine 5K Display appears to be affected by interference in some cases, caused by devices broadcasting a strong Wi-Fi signal. In testing by 9to5Mac, the monitor started having problems when it was placed less than 6.6 feet away from a router, causing the display to repeatedly disconnect from the MacBook Pro, and in turn causing the MacBook Pro to freeze.

After moving the monitor away from the router, LG's support suggested the display should be kept away from the router while the company works to "isolate the issue."

One clue that helped pin the source of the problem on Wi-Fi interference was an online review for the display on Apple's website, suggesting the issue is being felt by other users. The reviewer, identified as Patrick G, advises the symptoms he experienced as dependent on how much traffic was passing through the Wi-Fi connection, and that the screen would flicker or go black based on the proximity to a router.

The problem does not appear to affect all configurations, however. The unit reviewed by AppleInsider was evaluated during the course of the review within three feet of two different operating 802.11ac routers, and was not impacted by the proximity.

A second LG Ultrafine 5K unit tested on Monday also does not show the issue with wi-fi routers. A NetGear NightHawk X6 router was held directly on top of the monitor with no ill effect.

AppleInsider has confirmed that both LG and Apple engineers are examining the situation.

"At first analysis, it may be an issue with insufficient RFI shielding on a very limited quantity of the cabling bundled with the monitor," a source within Apple corporate told AppleInsider. "We're continuing to look into the rare trouble reports with the monitor."

The LG UltraFine 5K Display is considered a replacement for Apple's discontinued Thunderbolt Display, offering a 5,120x2,880 resolution, a P3 wide color gamut, and the ability to charge a MacBook Pro using the same Thunderbolt 3 cable used for video and data transfers. The monitor is on sale from Apple directly for $974, a discount of 25 percent from the usual $1,299.95 price.