Idle dropping on braking

Hey Everyone

I have a 2002 Escape XLT with 210,000 km V6 , 3.0

Recently when I have the brakes applied, usually at a stop sign, and with AC on, noticed the RPM drop from around 750 to about 500, just for a second and then back to normal.
Changed plugs last wknd and it appeared resolved for a day or 2, however today it happened again!
Also, it seems to be worse or more frequent with the AC on

Ive read online that it may be a weak battery or something to do with the Compressor

Any and all thoughts are appreciated!

Thanks to all!
Appreciate the support!

Sorry, I must have entered the forums in another area that day, then when I entered again the Escape didn't have a checkmark to indicate a new post. A few things I would suspect related to this vehicle. A dirty IAC valve. A vacuum leak. A main catalytic converter starting to clog with parts of the guts from the small cats that are part of the exhaust manifolds.