Why did German naval radar have so many problems?

Why did German ships appear to suffer so many radar problems?

British radar had matured earlier and was improved for reliability and survivability, while German systems were at a less mature point in their development cycle.

British radar had reached practical development earlier. That head start allowed engineers and crews to spend more time on reliability, maintenance, and survival after battle damage. German sets pursued high performance but had less maturity in service. The contrast is therefore explained as a difference in development stage rather than a sweeping national characteristic.