Are you using devices hooked up to the same router, though?

Because even with different device IPs, you're still going through a device gateway. And like CletustheElitist pointed out, the AI really is as sophisticated as it sounds.

Google is incessantly updating/upgrading it, and there's a bit of a shared synergy between other Big Tech corps across various social media services.

So if you use Facebook on one device and click through a link that leads you to YouTube, the AI takes notice of that.

If you use Twitter and go to YouTube, the AI takes notice of that.

If you leave a comment on YouTube from one browser and then use incognito mode on another browser, it's still tracking your IP address and collecting data based on that; they build profiles and keep track of the profiles they build on you. Permanently.

One of the ways this is achieved is through an AI tool called SensorVault, and once it logs your location and has profile data from that location (e.g., YouTube account, Gmail account, Facebook account, Android phone, Twitter account, etc., etc., etc.,) it then builds on the data it collects and tracks you. It's how they can still recommend ads to you even when you're logged out of your YouTube account or using incognito mode on a completely different device.

You can read a little bit more about it here: https://www.sysjolt.com/2021/big-tech-collecting-all-your-data/

https://anonymania.com/google-sensorvault-privacy-evasion/