This was seen in the OOBE screen but probably occurs anywhere

0. Disable WiFi to simplify repro (not necessary but requires extra scrollong if WiFi is enabled)
1. Insert a Cellular network dongle (it was one with no mobile networks available)
2. Wait for the 'Mobile data' section to show up above Wi-Fi
3. Remove the dongle and wait a few seconds

Observe: Mobile data section shifts to be below Wi-Fi and does not go away. Navigating away from the network page and back causes the Mobile data section to disappear.

This may be a side effect of creating a "default cellular" service.