[UKönig]

German radio/electronic systems education or knowledge during, and prior, the war years was abysmal. A lot of factors influenced this, but propaganda was the biggest culprit.
In short, the Germans always thought they were doing better than was actually the case. Radar electronics was no exception.
Allied deception led them to believe that their own radar detectors were giving off emanations that the allied could detect, without using their own radars, which is why the "latest" German development was inferior to the systems it was supposed to work against.
The allies were not aware that metox, Naxos, or wanze emitted its own weak radiation, but that the German designed equipment simply did not work as expected.
No, your boat does not have all available detectors installed, but only the latest version, which was generally unreliable.