This is not strictly WSJT-X related, but I'm not sure where else to ask without having to explain having a radio connected to a Mac :-)

I'm running 2.4.0 on my iMac (Big Sur) and my K3S is connected using USB. The K3S appears as two USB Audio CODECs in the Audio MIDI Setup tool - one each for input and output.
I can receive in WSJT-X if I select USB Audio CODEC 2 (the i/p device) but the average level is way too high ( 60db with only noise). Thus it overloads with strong signals.

Unfortunately, the input device has the level controls greyed out in the MIDI control panel, so I can't drop the level there; and of course WSJT-X has no i/p volume control.

Has anybody else experienced this problem? If so, how did you resolve it.
If you didn't, how is your K3S, Mac, WSJT-X audio chain configured?

73, Gareth - M5KVK