Google has disabled a warning when submitting insecure forms from a secure (HTTPS) page to an insecure (http://) URL. Google has been focusing on removing mixed-content in Google Chrome, when a secure page loads content from an insecure URL. The new feature went live for everyone in Chrome 87, and many website administrators began reporting problems in a Chromium bug report. Google will enable this feature again in Chrome 88, which is expected to be released on January 19th, 2021, but warning only on forms that directly submit to http://.
Source: https://www.bleepingcomputer.com/news/google/google-chrome-disables-insecure-form-warnings-after-complaints/