Thanks @thomasm.cz4eli, the screenshot helped!
It appears from the screenshot that you have assigned your wife’s number to her, as an assigned user. This means she can now view her call logs, but you cannot. To see them, you’d have to log in with her account credentials.
Here’s a better explanation:
If it always happens at work, then yes! You’ve narrowed it down quite well, and I’d guess it’s either the Wi-Fi network or the cell service at her office. I’ve seen phones send duplicate text messages in both instances - when the phone is on Wi-FI and the network is not great, as well as when the phone is on cell and the cell signal is weak. We can’t do much about the Wi-Fi at her office, but if her office offers multiple networks to choice from, then if she has a choice between a 5 GHz and a 2.4 GHz network, she might try the 2.4 GHz option. (Or if that is what she picked, select the other!)
I took a peek at coverage in your area, and it looks like both of our carrier partners have very good coverage in your area, but I do see pockets weaker coverage on the carrier her phone is currently provisioned for. Of course, I don’t know where she works - if you’d like to send me the address privately, you can click my username and click “message” to send me a personal message, and I’ll check the coverage at that location.
We offer cellular coverage through two different network partners. So if it looks like coverage isn’t ideal at her office with the SIM card she has now, we could send a SIM card that provides coverage with our other partner, and see if that solves the issue. If she works deep inside a very large office building, she might see improvement on the other carrier, anyway.