AAV whining sound and sewer smell remaining

[DrewNYoumake2]

Hi All! Was getting a sewer smell in downstairs bath (2 story house from 1975). Opened the wall to see that the vent was open to the air. Added AAV.
2 issues: 1. Now when toilet flushes, there’s a whining sound but not when sink drains. 2. Still getting a little sewer smell downstream of that pipe in the basement. Any thoughts?

 

[WC1]

Sounds like the valve is admitting air (hence whistling) on flushing.
You wouldn't expect it to draw air in when the basin drains.
The smell may be from a cause other than missing aav