Z3 Compact Boot Loop on one specific Wifi Network

[Gonzonator1982]

After working flawlessly for nearly a year, my Z3 Compact entered a boot loop on the 4th September. I narrowed down the problem to the Wifi; every time it authenticated on my Work Network, it crashed. The only way to exit the loop was to switch off the WiFi.

I tried the PC Companion repair tool, no luck, and even performed a factory reset, same. Then I noticed on the way home that it picked up the Tesco Wifi with no drama, and then at home it again worked flawlessly on my own WiFi. It was only at work that it crashed.

I asked around and found 3 other people experiencing the same problem, all of whom were Sony Xperia owners. Everyone with a Windows phone or PC, Apple iPhone or iPad or Samsung Android could connect as before.

Does anyone have any idea what is going on??

[YoGem]

If you are sure that the issue present itself when you are connected to your wifi, try to "forget" your wifi connection and the try to reconnect to your wifi, does it work?

If not, can you try connecting to your wifi in safe mode? Does it work?

If yes, you may have an app that is provoking the issue, but if it doesn't work...

.. Is your wifi router dual band? Can you try to disable the 5ghz band from your router and trying to see if the phone reboot with just 2.5ghz?

[Gonzonator1982]

Forget is the only way to stop the boot loop and keep wifi on, tried many times. Besides I have also factory reset.
Safe mode gives identical result.
Wifi band is not the issue since I have dual band at home, plus the hardware has not changed in the past year when it was working perfectly.
I don't think it can be a phone hardware issue since it is happening with multiple phones. It's very perplexing!

[YoGem]

Well, trying to disable the 5ghz won't take you more than 2 minutes, could you please try?

[Gonzonator1982]

Just in this morning and the 5GHz band is not enabled on the Access Point. Double checked using WiFi Analyser and there is nothing at all in the 5Ghz band.

[Gonzonator1982]

Further information:

So out of desperation I returned my phone to the Vodafone store as it was still under warranty (2 years on this device). They sent it away for repair, but found nothing they could diagnose so just sent me a brand new phone as a replacement.

(Thank you Vodafone, very generous of you)

The new phone behaves exactly the same way.:smileyangry:

Tearing my hair out here.

[Gonzonator1982]

An idea, if anyone is still reading this post; the problems started at around the time of the latest build updated to version 23.5.1.291. All the phones (4 now) that have been affected have the same build.

Could anyone tell me if anything in the latest build changed regarding wi-fi?

Could anything that changed be the cause of the problem?

Is there any (warranty-friendly) way to roll back updates to the previous (working!) build?

Does anywone know when the next build update is that will hopefully sort this out?!

[Gonzonator1982]

So I heard that Sony will not roll out Android Nougat to the Z3 Compact. Does this mean there will be no further updates to firmware EVER?! I am stuck with this phone which won't work at work?!

Going to take this one back to Vodafone again and see if they will downgrade me to a phone that actually works.

[Gonzonator1982]

Still happening.