Hi,
Went to 'Settings-->Mobile Networks-->Network mode'
The selected option was 'LTE/3G/2G (auto connect)'
I changed this to 3G/2G (auto connect) and it didn't make a difference.
I changed it back to 'LTE/3G/2G (auto connect)' and it worked. i.e. I could connect to wifi and run apps.
Just...