Webview: on some forms auto-fill kicks in contacting content-autofill.googleapis.com despite of auto-fill being turned off

Expected Behavior

With AutoFill-Service set to None in Android settings, no autofill would be triggered – especially not contacting 3rd party services, and very especially not Google's

Current Behavior

On some (not all) forms, we see connections being opened to content-autofill.googleapis.com and some other Google IPs, e.g. with Nextcloud logins (but not only there). We were using PCAPDroid to watch network traffic. Note this only happens with LineageOS webview – we were not able to reproduce on other ROMs including stock.

Possible Solution

unknown to me

Steps to Reproduce

See e.g. this issue with Nextcloud's SingleSignOn library were we collected details from multiple sources.

1. Start PCAPDroid to watch traffic
2. Use an app with e.g. Nextcloud SSO, and initiate signup for a new account
3. Watch the output in PCAPDroid
4. See mentioned connections being made
5. repeat the same on a different ROM and do NOT see those connections

As the device section is mandatory, let me point out this is NOT device specific. I cannot tell for sure what devices other testers were using.

/device FP2 /version lineage-17.1 /date 2021-07-06 /kernel 3.4.113 /baseband 4437.1-FP2-0-08 /mods microG, F-Droid

I have read the directions.