Chrome is experimenting with stopping autofill on forms submitted without encryption

To the codebase used to build the Chrome 86 release, added "chrome://flags#mixed-forms-disable-autofill" setting, which disables autocompletion of input forms on pages loaded via HTTPS, but sending data via HTTP. Autocompletion of authentication forms on pages opened via HTTP has been disabled in Chrome and Firefox for a long time, but until now the sign for disabling was the opening of a page with a form via HTTPS or HTTP, now it will also take into account the use of encryption when submitting data to the form handler. Also, in Chrome added a new warning informing the user that filled data is being sent over an unencrypted communication channel.

Source: opennet.ru