LG UltraFine 4K display randomly flickering

TLDR Plug an external power adapter instead of relying on the monitor to power the laptop (if using with a laptop). Play a LCD screen burn-in fix video full screen for a few hours. Context I have a LG UltraFine 4K monitor (24MD4KLB-B, the one made in partnership with Apple in 2019 for deep macOS integration). This year it randomly started flickering. Literally once second it was OK, and the next…