Nari ultimate issues

Hello,
in advance sorry for my English I am French.

I purchased a Razer Nari Ultimate in September 2020.
For the last two weeks I have been fighting with the headphones to make it work properly.
For example before I used it wirelessly without any problems and when the battery started to weaken I plugged in the usb cable and I could continue to play by letting the headphones charge. But now when I plug the cable in, the sound just cuts off and I can't hear any sound no matter what I do. So I can't use it if connected via usb (synapse doesn't even detect the headphones in usb anymore).
In wireless mode, regularly the headset disconnects and is not detected by synapse anymore, I have to turn it off and on several times in a row because 80% of the time when I restart it, I hear the sound 2-3 seconds and then it cuts off.
There is another problem, if I touch the microphone, it happens very often that the sound goes off, and again I have to restart it several times.
I reinstalled synapse, re-installed the last firmware but nothing works.

Hopefully someone will be able to help me.

Have a nice day and a happy new year.