I haven't seen or heard of that model. My son uses those Logitech headsets and from memory a G4 or something.
Your killer test was the old mic is fine. That means this headset is going back. At least here it would.
So I just bought a new wireless headset for myself. It is the "hyper x cloud stinger" and was bought around christmas time (so really new). I started to use it christmas day and had no problems then. The audio quality was great and I did a personal test on discord for the mic quality and it sounded good as well. Then I start to talk to other people and they all say it is a bit muffled. After the 3rd or 4th person told me so I knew something was wrong. My old headset's mic works fine with the same ports .so there is no issue there. Did I buy a faulty headset or something?