Turns out the issue is down to weak wifi. Strange as I never had trouble controlling it manually, but I submitted the logs and they identified its disconnecting intermittently. I guess this causes it not to run the schedules. Odd that they have the Offline schedule just for that purpose, but it doesnt seem to apply. Anyway I put an extra AP outside and improved the signal from -80 to -75 and it seems to run reliably now.