We have been running into an issue with our Latitude 5410, 5420, and 5430 model laptops, as well as the Precision 3480 models, where the cellular option disappears.  We have run Dell Command Update on numerous devices in these model ranges to confirm that BIOS and all drivers are up to date, but we keep running into this issue.

It's most noticeable when the laptop has been undocked from one of the WD19/WD19S docks that we use in our environment.  Dell Command Update has been run while docked to ensure that the dock has received all firmware updates.  

The only remedy we currently have is to restart the laptop when cellular disappears.  This is not ideal due to the potential loss of work and, to be honest, it's incredibly frustrating to find out that you have no cellular after you've already left the building and are remote. 

It should be noted that restarting doesn't always ensure that cellular comes back up and it doesn't 100% guarantee that it's not going to disappear again.  One of my end users had it disappear after her laptop idled and locked her out, and she absolutely needed to have cellular to testify in a court case.

Any assistance by anyone would be greatly appreciated.  I've gone through the forum a little bit and wasn't really able to find anything that could resolve this issue.