Ventilation help?

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N2583

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I recently installed an AAV under a vanity sink to deal with possible ventilation issues. This worked well and ended up getting stronger pressure from the sink and no gurgling. However, Now, when I flush the toilet air pushes out from the AAV fitting and into the AAV closing the vent and not allowing the toilet to flush.
I have no water backing up in any other sink or toilet. I snaked 25ft to check for clog (pipe measures 50ft total), I also used a powder drain opener.
What is causing this positive pressure to shoot back into the AAV? When I take the AAV off the toilet flushes well but I can still feel air blowing out of that fitting causing it to close and allowing no vacuum to suck the air in and flush the toilet.
Thank you.
 

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Geofd

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Could be that your main drain is partially clogged, if you pull the toilet you could run a mid sized snake out further than 25' or you could try a new aav
 
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