Chosen Solution
My spare iPhone 7 A1660 has some weird issue. It was used so I wiped the phone. the WiFi toggle was greyed out. Now it’s back on but this happens every time I reboot the phone. I did flash the phone with 13.6.1 as it couldn’t activate itself because it needed an update. I am going to get a new dock connector and battery for it as it has 1233 charge cycles on it. I have seen that sometimes it is a board-level repair. I don’t like messing with the logic board so I would buy a new one if it’s not super expensive. Thanks!
Yeah it’s most likely a board issue. The iPhone 7/7+ was notorious for board issues. If you swap boards make sure you get the corresponding home button because they’re paired to each specific board. You can order a replacement home button if need be but you’ll lose touchID.