Chosen Solution
My iPhone just says searching/no service even with different carriers. WiFi and bluetooth still work and nothing is blank in the about page. Sometimes if i’m VERY lucky i’ll get one bar for about 30 seconds and I can load a webpage.
Turns out it’s a gsm only phone so that is the issue.
I use to have this problem with my 6s and my normal fix is to remove the sim restart the device and put the sim back in. If this doesn’t improve try doing the same thing but instead of restarting try factors resetting the device.
I have the exact same problem