Problem with 45min interval within 08:00 to 18:00 over multiple days

[MoInMaRvZ]

I have a problem with recuring events in 45 minutes interval. The event should recure on january every Mo, Tu, We, Th, Fr from 08:00 until 18:00. See following input in picture. The result an Tue 04.Jan 2022 starts not at 08:00. It starts at 08:30. Is that a mistake in this library or is it my own fault?