Chosen Solution
Sometimes when I do reset network settings, my wifi and bluetooth will be okay for few minutes then my iphone will restart and then wifi will be greyed out. I’m on iOS 12.1.2 I recently visited a nearby unauthorized shop to replace my lcd and battery. What could be the issue? Could it be hardware? Also,
Sure, it’s possible that a hardware failure occurred, but based on the information you gave us, we have to rule out software first. You could try backing up the phone through iTunes to a computer and then performing a DFU mode factory reset. Connect the phone to the computer and open iTunes and perform a “Full Backup” to the computer. After this completes, enter DFU mode and factory reset the phone. Once completed, restore from your backup. DFU Mode: Step 1: Connect your iPhone 7 to your Mac or PC with a Lightning to USB cable. Step 2: Press and hold the Sleep/Wake button and the Volume Down button simultaneously for 10 seconds. Step 3: Release the Sleep/Wake button while continuing to hold the Volume Down button for 10 additional seconds. Unlike Recovery Mode, which presents a Connect to iTunes message on the screen, the iPhone 7’s screen will remain blank while in DFU mode. Step 4: Launch iTunes, and you should see a message stating that “iTunes has detected an iPhone in recovery mode. You must restore this iPhone before it can be used with iTunes.” Should this not solve your problem, you very well may have a hardware issue which may require some parts replacement. Try the DFU mode restore first and then we can go from there.
I would replace the wifi antenna firs and see what happens.
