For awhile now, we've heard about some Switch owners having trouble with third party docks. Most of the attention has centered on Nyko's Switch dock, which has lead to many a bricked Switch. This only seemed to escalate with the Version 5.0 firmware the Switch recently received. Nyko has been aware of the issue since the first reports came in, and they're still addressing the issue after Version 5.0.
“We are aware of the issue some Portable Docking Kit owners are facing after updating the firmware on their Nintendo Switch to version 5.0. Though further testing is still required to determine the exact root cause of the problem, we believe it is related to the way the Switch handles AV output for an external TV/monitor while the console is docked on the Portable Docking Kit.”
When Nintendo was contacted about the Switch third party dock issue, they didn't come right out and say the recent firmware update was the problem. As usual, they commented on the matter in a roundabout way.
“Unlicensed products and accessories do not undergo Nintendo’s testing and evaluation process. They might not work at all with our game systems, and they could have compatibility problems with certain games, the Nintendo Switch system itself, and other licensed accessories and peripherals.”