3.5mm jack adapter not working

[SPLiverpool]

I purchased the Xperia 1 two weeks ago and I'm using in the box 3.5mm headphone Jack adapter and the headphones provided.

They were working fine for 12 days, however yesterday they stopped working and the sound is now being outputted from the handset even though the headphones are plugged in.

I've tried restarting but that didn't work. I've also tried restarting in safe mode but this didn't fix the problem either.

Any ideas as to what the problem is and how to resolve it?

[SPLiverpool]

Okay so I used to have this problem with sound not outputting correctly on my z5 premium.

So I was using soundabout app to force audio to the headphones.

Couldn't find soundabout on play store, so i downloaded "Lesser AudioSwitch" which has seemed to fix the issue and I now have music outputted through my headphones.

So it looks like a software issue with the handset? 

This is just a temporary fix I'm hoping for a permanent fix...

[Karim]

on Z5 it was a hardware issue... headphone jack not detecting input. Would you change the 3.5mm  to usb-c cable and try? if that's not helping I guess it would indicate a hardware issue since the phone isn't able to detect the headphones and the only option is to force the output via app.