[AC Question]

For the past two days my Samsung S7 Edge has been giving me problems by not connecting to T-mobile's network. I have no cell reception at work so I normally use the Wifi calling, when I return home I noticed that my phone has been taking longer to connect to T-mobile's network. My phone seem to be working fine last night as of 11:30pm but this morning my phone will not connect to the network no matter what I do.
Everything I tried does not work: I restarted my phone several times and I tried creating a new Access Point Name (APN) and I just did a factory reset. My phone still says "No Service"
I am unable to use the wifi calling at home because the signal is not very strong in my room.
I'm pretty sure it is not my sim card because when I put it in my old phone it works fine.

Please help!