Hi,

I’m a bit confused and surprised by something I’ve noticed. It doesn’t really cause me any problems, but I didn’t think this was even possible, so I’m trying to understand what’s going on.

Setup

I created a brand-new, dummy “anonymous” Google account.
Fresh GrapheneOS install.
Created a brand-new, temporary user profile.
Initial setup was done on free public Wi-Fi.
No phone number verification was used.

Profiles

Owner Profile

Google Play Store + Google Play Services installed.
Logged into Play Store only with the dummy “anonymous” Google account.
Apps are installed here, internet access is disabled afterward, and the profile is never used for anything else.
Apps are “pushed” from Owner to Daily Profile.

Daily Profile

Google Play Store is disabled and has no network access.
Google Play Services is enabled with the minimum permissions required.
WhatsApp Business installed via the Owner profile.
Logged into:
- WhatsApp Business
- Google (only for Google Contacts sync)
No other apps are logged into or even used (Instagram, Facebook, etc.).

What I noticed

When I open Google Play Store in the Owner profile (logged in with the anonymous Google account), and look at apps I’ve installed in google play, Play Store shows:

“Available on more devices – Xiaomi phone”

That Xiaomi phone uses my real Google account, not the anonymous one.

The confusing part

How can a dummy, anonymous Google account in the Owner profile be aware of:

My Daily profile’s real Google account, and
Another completely separate phone (Xiaomi) using that same real account?

The anonymous account:

Has never logged into my real Google account
Shows no visible evidence of being linked
Was created fresh and separately

Possible explanations (guessing)

Somehow the Owner profile’s Play Store is learning about the Daily profile’s real Google login through the same GrapheneOS device?
Since my real Google account is used on both the Daily profile and the Xiaomi phone, Play Store is correlating them indirectly somehow to the Owner Profile?
Possibly via phone number association due to the sim card insalled in the GOS phone.

Phone number?

My personal SIM is in the GrapheneOS phone.
The anonymous Google account was not given a phone number.
Could Google still be associating the SIM/number at the device level and linking accounts that way?

Extra info

No phone number was provided to the anonymous Google account.
Both profiles have connected to the same Wi-Fi networks, including my home Wi-Fi (after initial setup).

Hopefully this makes sense. I’m mostly trying to understand how this linkage is possible from a technical/privacy perspective.