I believe it is a Logitech or AMD driver issue.
I think it is recording in 7.1 although I am selecting stereo on the headset
Update 1:
I did a test removing the Ghub software and recording is fine using the G933 headset, I say this is Logitech driver issues
Update 2:
Settings for this is found under settings and General in Relive software
So I am not sure if this is AMD or Logitech.
In AMD Relive if you select "Seperate Microphone Track", the audio seems to be fine.
Tested and the level on Recording and Youtube clip is identical, quality also.
So if you edit your videos, I would recommend that. I will do that from now on, kinda of a "dah" moment for me :)
If you normally don't edit try setting the "Audio Boost" to low.
Please note that I haven't tested how this works on actual in game where I also use chat and my own microphone, but recording and Youtube clip seems to be identical level. Although the quality is a bit lower on the recording.