On at least 5 separate occasions in the past month or so I've noticed that my cellular connection just quits. Typically I get 3-5 bars just sitting in my office at work. On random days, I've looked down to see the circle with a line through it indicating no connection. Others on AT&T in the area are connected just fine, with quality signals. I've attempted to shut off cellular through setting and turn it back on, put it in airplane mode and turn it back on, and still, no signal. The only thing that seems to work is a good old fashioned Windows reboot. This is extremely annoying and very frustrating. Obviously, phone calls and texting doesn't work while the connection isn't working. I use my phone for business and personal, so who knows how many phone calls/texts I'll miss or the importance of those.
I recently had another issue with both the store and calculator apps not working. After waiting a week with no community answer, I simply had to reset my phone to restore functionality. The cellular issue happened again today at work, so the reset did not fix it. Just to be clear, this has happened at home and I noticed it once when leaving the grocery store. It's not location specific and I do not live in a rural area. Based on all the bugs so far, I have to assume it's a Windows 10 Mobile issue, but it certainly could be hardware related.