T-Mobile Note 4 Slow to find Mobile Data

[AC Question]

First of all, the coverage where I work is rather poor, and essentially non-existent inside the office. Outside, I can get usually 4g(not LTE) speeds but only 1 or two bars. That being said, I'm mostly on wifi while I am at work on my phone. But when I leave the office and turn off wifi or leave the wifi range, my Note 4 takes forever to find a data connection. Would you know any solutions for this? This happens at my home as well, when I get in the car before I start driving to check traffic, the phone won't connect to mobile data for a long time, sometimes up to 10 minutes or more. Usually restarting the phone fixes this, but I'm hoping there's a solution so I don't have to restart my phone everytime I leave wifi so my phone can establish a data connection. Any help would be much appreciated!