No Cell Coverage Battery Drain

I recently purchased an iPhone 13 Mini a few weeks ago. I've noticed that while at work I have a lot of battery drain, despite my phone pretty much being unused much of the day. When I looked at my battery settings, I noticed that anywhere between 75% and 90% is attributable to "No Cell Coverage". I do work in an area with next to no coverage while indoors, so the fact that the phone is showing limited to no coverage is no surprise. That being said, I connect my phone to WiFi and have WiFi calling enabled. I live in a big city, so the only place this could be happening is at work. My spouse purchased an identical phone at the same time, and does not see this, although they work in an area with good service. My previous device was an iPhone SE (2nd gen) and did not experience this issue.

Is there something wrong with my device? Any settings I can tweak to possibly mitigate this battery drain?

Thanks!