Preferred network is stuck on automatic

[AC Question]

My galaxy s6 said I went too many days without restarting my phone. So I restarted it and now my preferred network is stuck on AUTOMATIC.
Now I coincidentally have no service and sprint has no 24/7 tech sorry support, WTF!!??

 

[Tim1954]

Take out the sim and give it a gentle polish... Sometimes you get build up of electrolyte that blocks the current flow...