Performance problem with Dell Precision 7550 with WD19DC

When my WD19DC is plugged into my Precision 7550 and I start using CPU+GPU-intense applications, after a few minutes the performance degrades a lot (like running off the battery) and I can see the power LED going on and off in longer intervals. Turning off Turbo Boost did not help either. This problem does not happen with the regular charger cable when the WD19DC is not connected.

Basically it's quite similar to the problem reported here: https://www.dell.com/community/Precision-Mobile-Workstations/Precision-7740-battery-drain-WD19DC-240W-adapter/m-p/7767959/thread-id/4981

Is there any way to fix this problem? These performance drops make using resource-intense applications virtually impossible (barely a "design feature").