Question about Midland G9 Pro

Basically, this would be the right headset:
Midland Headset Security MA 31LK Pro

But it did NOT work for me. I "rang out" the headset (measured the ohms): The signals were connected incorrectly. The speaker on the thin plug, the microphone on the thick plug = wrong. I received a refund from Digitec without any problems. I then soldered something together myself using a different pair of stereo headphones (speakers only).
It is therefore not clear whether the next headset you buy will work correctly (was it a series error by the headset manufacturer or was it a single copy that was wrong!!!!?????)
Try it out immediately after purchase and if it doesn't work, measure the thick plug ohmically. It must have between 25....35 ohms between the front and the next part of the plug! Kbt