Connect MacBook Pro to Dell Monitor
I have this exact same monitor that acquired about a 18 months ago (or so). That particular monitor requires a Dual Link DVI connection and most mDP to DVI aren't Dual Link.
The one product that I found that worked really well was Kanex iAdapt Mini DisplayPort / Thunderbolt to DVI Adapter + USB
I tested this on an iMac 27 (Catalina), a 2009 MacBook Pro (El Capitan), and a Surface Pro 3 (Windows 10). All were able to display full resolution with no problem. I'm now using it on a Dell workstation running FreeBSD 12.1-RELEASE and I've had zero issues with the adapter.