Password save prompt for existing entries

When I use the auto-fill feature (via pop-up, shortcut, or auto-fill setting) Bitwarden will still ask if I want to save the password to my vault. However, it is obviously already save in the vault as I just filled it from there.

Is there a setting I have mis configured?

OS: Windows 10
Browser: New Edge Version 85.0.564.44 (Official build) (64-bit)

My guess is that URL in BW item is different to one in browser.
It is similar enough to perform auto-fill, but not enough to map that item to the site, so BW asked to store creds as new item.

And my other guess is that the password in BW and password in the form at submit time are different, so that BW detects usage of different password and asks to store it.
This could be caused by some security features on the page, which intercepts password on type and replaces it by some random chars, so that browsers and other intercepters won’t get your real password (but malicious widgets on the page and keyboard sniffers still can)