Data usage showing 0 (zero) for almost a month

I've been on the 1.2TB/month plan for a few years now. Until this month, my data usage has appeared correctly in the Xfinity app. Starting in May, data usage shows zero. This is incorrect, as there haven't been changes in my data consumption. 

I called the Xfinity Customer Security Assurance Team and talked to one of their reps last week. She put me in contact with another Xfinity support rep, who told me they would look into the issue and get back to me in 2-3 days. That has not happened.

How do I get the data usage information back in the Xfinity app? I tried reinstalling the app, but that didn't help. 

If you see my data usage on your end, please let me know how I can see it on mine. If you don't see my data usage, that would be a bigger problem, as I cannot see a way to check for going over the monthly data consumption limit.