Does Instagram know what Google account I'm using?

I have a question does Instagram know which Google account I’m using? I created a second Instagram account on the same phone, using the same IP address, and I’m still signed into the same Google account as I was with the first Instagram account does Instagram know that I have both insta accounts on the same Google account? Both insta accounts are not connected or linked to Google and were created using different emails addresses.

Instagram doesn’t need a direct link to your Google account to make the connection ,device fingerprinting, IP, user behavior, and even app data can be enough for correlation.
If both Instagram accounts were created and used on the same phone with the same IP and Google session active in the background, there’s a strong chance Instagram can detect they're related.
Even if the emails are different and accounts aren’t officially linked, the metadata often gives it away.

For large domains, instagram may know, however, they do keep track of which domian for emails are being used and at which number.

Instagram won’t directly see your Google account unless you link it or sign in with Google. But since both accounts are on the same device and IP, Instagram can still connect them through device IDs, cookies, and app data. Google account itself isn’t the main link here.

Even if emails are different, using the same device and environment can link accounts together. For separation you could try to use cloned apps, different user profiles, or virtual environments.

Yes, Instagram can detect links between accounts via device info, IP, cookies, and Google account sessions, even if emails are different.
To reduce linkage, consider using different browsers or isolated environments.