Yes, there seems to be some strange logic behind the chip. I have a device from another company with a similar display.
Sometimes the clock is "in" in no time and sometimes it takes forever. But normally it should come via RDS or DAB+ signal. I haven't tried internet radio yet. Maybe contact Grundig about the problem.

... will NOT start...

Sorry, no idea. We have 2 devices: 1 works perfectly, one spins around and can be started ... summer time cannot be set ... in short, not really usable.