Unfortunately, mobile networks acting as a home ISP are still the same as using tethering on a mobile phone with your computer, despite all the clever marketing. The modem T-Mobile provides is basically a giant mobile phone in a box. These services rely on line-of-sight to complete a connection between your home and the tower, then connect to the internet using other towers or satellites.
Mobile networks, like T-Mobile 5G Home Internet, aren’t as stable as landline broadband and are not optimized for gaming. In many cases, your gaming traffic will be deprioritized by the mobile carrier in favor of people using social media or streaming videos. This deprioritization might be causing you to get routed to a lot of different servers outside your region. (Source: Me. I worked in telecom for over a decade.)
I’m not in Ohio, but if I use a VPN to Cleveland while connected to landline broadband, Overwatch places me on the Chicago server. This further leads me to believe it’s a symptom of the type of connection being used.
For the reasons I’ve mentioned, 5G internet doesn’t meet Blizzard’s system requirements for Overwatch 2. I realize that other internet options aren’t always available, so there may be nothing you can do to immediately correct the issue. However, the connection quality requirements have remained the same since Overwatch 1 launched.