You have unsynced jobs. Reasons can be vary: you were offline, Trucky had issues connecting to the Internet, the internet connection was unstable, you have experienced performance issues preventing Trucky to sync properly.
Seems there is something blocking Trucky from accessing the Internet or Internet is disconnected. Usually a full Trucky reinstall should fix this issue.
Invites allow users to join your VTC without needing to apply. Each invite can be used once and has an expiration date. You can create multiple invites with different expiration times.