The Integrated Schedules Processing Rule provides a variety of attendance flags you can create for your client, based on an employees schedule. This rule also causes the system to flag incomplete punch sets (punch sets that are missing a punch) with the message "Employee is not scheduled to be at work". I was told that schedules can only apply to completed punch sets, which is why the system views this entry like the employee has no schedule, but I think the system shouldn't be flagging these punches at all, as it is confusing to the client.
I recognize you can resolve the error by correcting the missing punches, but I think that flagging these punches still creates confusion for the client. If it is impossible to stop flagging these punches, then changing the alert icon/message that displays would create a better experience.
This appears to be a bug. Thank you for bringing this to our attention.