That is correct (at least in my case). If it starts stinking then I switch on recirculation and within a minute it starts smelling normal/neutral again. Once I switch it back to fresh air, it starts stinking again.
If it's a dry day then sometimes it won't stink at all. But the combo of rain/mist + fresh air intake guarantees odor.
There were discussions elsewhere about an updated part ("INNER DUCT, HVAC, PLENUM, M3, 1107204-00-E") so I had that installed, too, but it did nothing for me.
I do hear air being pulled in after the car sits for a while, so I know that the firmware update from a while back is trying to do its job of drying out the system.
Now I'm trying to leave A/C off for cabin overheating protection. I tried this in the past without success, but maybe I need to do it for a longer period of time.