I used Google Search in Chrome incognito mode without logging in to my account, so no cookies were stored. However, somehow I instantly got a bunch of ads relevant to my search on Instagram. There were normal Chrome tabs in a separate window where I was logged in. Does it mean that Google used my IP to link requests from anonymous sessions to my profile via cookies in the normal tabs (and subsequently passed my data to Meta)?
As far as I know, it's stated that Google doesn't use the IP for this purpose. However, I personally didn't come to any other explanation so far.
Were there some investigations related to this matter that I can read?
I know that I can use another browser with a VPN extension so my requests will no longer be identifiable via the IP to solve this problem, but I'm curious about the exact mechanism of how my data leaked.