"2019-06-28 10:57:16 W  Enrollment from iOS requested but no APNS certificate provided. Enrollment profile not sent."
This means MDM does not have configured (or configuration failed to apply) APNS certificate. Ensure you have policy assigned to MDM and it's actually applied. You can check via Configuration -> Get on device on which MDM is installed. "AdminConnector: Connected: true" means connection between managing Agent and MDM works (it's the chanel policy is delivered over). If this is correct change something in policy (log level etc..). Agent sadly does not attempt to send policy multiple times, so it's possilble failed delivery attempt caused this state.
If you can't figure out why policy isn't applied please contact support instead, we can't request relevant log files over forum.
Please also check You meet HTTPS certificate requirements, they differ for Android and iOS.