Docking Station Woes

I'm helping someone troubleshoot some strange issues with their WD19TBS docking station and Dell XPS 15 9520. They primarily use the docking station while using the laptop, but this week decided to work from a new location. They tried using the charger that came with the laptop but it wasn't providing a charge. They decided to just go back to the docking station since the laptop was about to die, but received a battery notification from Windows stating "Slow Charger: To speed up charging, use the charger that came with the device.

I confirmed the user is using the 180w power supply that came with the WD19TBS and I also confirmed they're using the Thunderbolt ports rather than the USB-C ports. We have attempted installing just about every driver I could find for this model laptop and docking station.

Looking for some direction on what could be causing this issue.

Side note: The user also mentioned the 2 HP 27er monitors they use with the docking station are randomly flickering throughout the day. This could be related to an overall docking station issue, but not 100% sure about that.