ZF3 using from Hong Kong, with same issue, after update One Ui 5.0 to 5.1 and the phone restart it could not go on Wi-Fi. Tried "General Management" "Reset" "Reset network settings" did not work, tried "Factory Reset" and did not resolve it.
Brought it in to service center and had the same telling me the Wi-Fi module is damage and need to change it, but because its link to the LCD it will need to be change as well (repair cost 4200hk$ 535US$ **bleep**) after 2 day back and forward they told me they give me 50% off the repair cost, as I did not want to wait anymore I paid for the new quotation and now waiting for my phone to get repaired because I press update 5.0 to 5.1 lol.
Haha.. if they can give 50% discount, it means they acknowledge this issue is common among ZF3 users and yet, not offer a one-time complimentary repair for affected users from updating software update.
