Its a Samsung galaxy s7 and the OS is up to date.
I also tried on a Media Pad and got no logging also.
Stopping and starting the SDK seems to bring it back so no big deal; I am using version 6.30 if that makes any difference.
Thanks Erel, I will upgrade when I get the chance, bit busy right now.
As it happens logging is working again and seems stable, most odd.
Will start a new thread if I get any issues after upgrading.
Thanks