I work in a building with thousands of other people and Verizon users are the only ones unable to use their phones! I have a guy with a Sprint and a guy with an AT&T and their service is fine. Anyone else have this issue?
If this is in a city and the majority of the users are on Verizon, the local cell tower handling that location might be exceeding the maximum device limit per cell. Have you worked with mobile support on this? Do you have any sort of signal or does the phone go from LTE to 3G to 1X as the day goes on?
What will make it worse is that there can be no priority for voice and data. Right now Voice always has priority over data users during peak times. Now that can't happen with the NN rules. Service will get worse for all providers including those who like cable TV.