Yeah, Aliexpress is blocking all kind's of bike lights shipping to Germany, unfortunately. The radar is a bike light in the end.
This is because of our street laws, as every bike light need a "K" registration with the KBA...
Yes, I know, that's foundn in § 67 Abs. 4 Nr. 2 StVZO (that's the German Road Traffic Regulations), "Blinkende Schlussleuchten sind unzulässig" = flashing tail lights are not permitted.
In the explanatory memorandum you find the reason for this ban - car drivers would not be able to judge the distance to a bicycle with flashing tail light in the dark.
I'm not kidding. Everywhere else in the world flashing tail lights are allowed. IMHO they're WAY SAFER that steady tail lights (the intensity is regulated in Germany as well).
German car drivers seem to be from a different breed than in the rest of the world.
I'm a lawyer by profession.
Did I say laws can be dumb stupid?
To be honest I'm surpriesed the Chinese vendors do not give a shit about it.