Sms notifications not working

Hi all,
Anybody else having issues with sms trigger notifications. This was working well and has now stopped without out any changes made.
Recreated the trigger - same result
Tigger count increases
Sensor data stream verifies event detection
Added email notification- this portion of the trigger works and email received
Changed the phone number - same result
Notification count less than 10 per day

So, trigger engine appears to be working. Is the sms gateway limited to a capped number of notifications per month on the free tier?
Is the sms gateway in maintenance mode?
Or is it just me!

Thanks all!

I am having the exact same issue. Any resolution?