What you are describing sounds like it may be related to the bypass air control valve (BAC). This is basically an idle control valve. It allows air to enter the intake manifold when the throttle plate fully closes. If it didn't, the engine would stall.
So, here is what I suggest. First, locate the BAC. it is under the throttle body. Inspect the connector to it and confirm there is no evidence of wiring damage, and the connector is clean, tight, and free of corrosion.
If that checks good, the next thing I would suggest is to service it. Here is a link that shows how it is done:
Try this. This component is what is responsible for maintaining engine idle speed. I attached a pic below showing its location.
Let me know if this helps or if you have other questions.
See pic below.
Image (Click to make bigger)
Saturday, February 19th, 2022 AT 8:21 PM