In case Always On is disabled, enable this feature and see if that makes any difference.
By default, web apps are unloaded if they are idle for some period of time. This lets the system conserve resources. In Basic or Standard mode, you can enable Always On to keep the app loaded all the time.
Just to confirm, ensure the CRON expression has ‘schedule’ append.
{
"schedule": "0 0 14 4 1/1 *"
}
Ensure it is deployed in the right directory/ triggered job copy your binaries to: d:\home\site\wwwroot\app_data\jobs\triggered{job name}
To get more details on the issue, review the logs and let us know.
Navigate go to the url: https://{sitename}.scm.azurewebsites.net/api/triggeredwebjobs/{jobname} (remove the job name to see all triggered WebJobs)