as per the similar questions below asked in 2015, I went ahead and bought a Samsung UW Monitor (LS34C500GAUXXU), connected my MBA (early 2014 - Big Sur 11.7.6 / 1.4Ghz DC i5 / 4GB / Intel HD 5000 1536MB) via a mini-DP to DP (iVanky 4k@60Hz), and have run into issues.
At first the Display terminal showed a connection in the arrangement window, and I could swap main displays to see the Samsung display settings, but nothing showed on the Samsung screen (black screen, but mouse disappeared along with windows if I moved them over). Then after unplugging and trying again, it kept on connecting and dropping out every 2 seconds. Now nothing registers... Any ideas warmly welcomed!