FZ 1000 WiFi intermittent working

[Lumix learner]

Has anyone had trouble with the WiFi transfer to their smart phones?
My camera works great and until this week I could transfer photos to my phone.
Now it gets half way through transfer and stops.

I've reset the camera, the WiFi and reinstalled the app.

I wondered whether there's a buffering part that creates a cache that needs clearing?

Any suggestions welcome