Dell U3224KBA DP to mini DP cable

Hi, I have a Dell U3224KBA monitor that I want to connect with a DisplayPort cable. The only issue is I could not find a DisplayPort to mini DisplayPort cable (this direction), to connect the monitor to my PC. This is incredibly frustrating, and I don't want to use HDMI cables, because I want to use Ubuntu and on Linux I can only achieve 4k resolution on HDMI (the HDMI 2.1 cable is certified and stable otherwise, and on Win supports full resolution).

I have had a mini DP to DP cable that should have been bi-directional, but the signal kept blanking out from time to time. 

So now I'm looking for a certified bi-directional DP to mini DP cable. It has to be at between 1.8m-2m (5.9ft - 6.5ft). Are you aware of such cable?