Cannot Connect to Skype Business/Citrix When Laptop Connected to Dock  

When I connect my Dell Precision 3520 to my Dell WD-15 dock, the laptop's wifi and cellular are automatically turned off. All network connectivity goes through the dock's gigabit ethernet. The laptop is connected to the dock via a USB-C cable that also charges the laptop. Normally everything works fine.

However, since 1809, I cannot connect to Skype for Business Basic and Citrix Workstation. Both are connecting to the same domain (my work domain). As soon as I unplug the dock and wifi turns on, everything will connect. I can still connect to other internet services during this time: web browsing, Skype Personal, and even Outlook can connect and send/receive emails from my work domain.

I'm not even sure where to begin troubleshooting this. I'm hoping someone can help point me in the right direction.

Is there a way I can disable the ethernet on my dock so it stays connected to WiFi?

You can unplug the Ethernet cable from the dock to prevent switching from WiFi. Or you can disable the device in Device Manager when you're docked.

As for losing your Skype/Citrix access when you're docked - that's probably a question for your IT department. Does Network Connections show you connected to the domain? Are you able to access other network resources in the domain?

I can't access anything in the domain. My dock is at home, so it's connecting from home and not a work wifi to ethernet situation.

I didn't realize it would be as simple as unplugging the cable. :O

This appears to be Skype for Business that is causing the problems. I can access/load the app without problems when not connected to the dock. However, when I connect my laptop to the dock, Skype will not load (after 10 minutes of waiting). Force closing and restarting the app didn't help.

After uninstalling the app, I hooked the ethernet cable back up. I'm able to access Citrix now.

Not sure what is going on with Skype for Business in my setup, but it's definitely toxic.