permanent error: Full page test creation fails - 1 min gets posted altough 10min is selected on the form.

I can't seem to create a Full-Page test: on the creation panel, the '10 min' checking frequency is selected, and disabled. But when Finishing the form, in the summary screen, '1 min' latency is shown. When I clikc finish, the system throws an error, that it cannot be 1 min, it has to be at least 10. This happens all the time. Seems like a bug.