Nintendo has received multiple calls about the devices being completely bricked and is offering to repair the device if it is under warranty, but sadly recovering any lost data won’t be happening.
A Nyko representative recently told Kotaku:
…[we’re] 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.
Nyko says it is working on a solution and has policies on replacing malfunctioning products.
Nintendo just rolled out another firmware update that offers “General system stability improvements to enhance the user’s experience”, and has issued a statement recommending that Switch owners only buy officially licensed Switch products, adding:
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.
Cop out response, but we expected that.