Latitude 7320 and LG 38WN95C-W keeps resetting Thunderbolt connection

Hi everyone, 

i recently got a new display to upgrade from my WD19TB-Dock (which fan is driving me crazy) and HDMI-display combo.

The new display is a LG 38WN95C-W, which features a Thunderbolt 3 connector with 94 Watts power delivery. Sadly if i connect my Latitude 7320 via TB-cable to the display, the display is shortly connects and shows the image, but after some seconds gets disconnected and reconnected again in an endless loop. The Thunderbolt-Controlcenter-Software shows the display when it is connected and removes it, when it disconnects. 

Interestingly if I connect my WD19TB to the second TB-Port of the Latitude, the display works without problems, so I suppose it's a problem with power delivery. Fun fact - if I use the power adapter that came with the Latitude (which connects to TB-Port too) instead of the WD19TB, the display also reconnects forever. 

Any ideas would be great - the workaround with the Dock als Power Supply is some kind of annoying (and still keeps bothering me with it's fan). 

Thanks