Unable to login into typo3 backend using chrome

I have weird problem in fresh TYPO3 9.5 and 8.7 installations.

Trying to login into the backend

• login with correct username/password, a few secs of load indicator and then the login form is shown again. No login possible.

• login with invalid username/password, as expected "Your login attempt did not succeed Make sure to spell your username and password correctly, including upper/lowercase characters."

There are other problems which are maybe related:

• Renaming a file in the File module seems to do nothing, the file itself is renamed. The new name is displayed only after a total refresh of the page.
• Deleting log entries. Clicking a log entry deletes it but the list is updated only on refresh
• other situations where changes are not reflected in the browser until the page is reloaded.

This happens on MacOS Catalina 10.15.2 / Chrome 79.0.3945.88?

At the same time Firefox seems to work.

Chrome seems to work normally everywhere else.

Found a solution:

Even creating a new news entry did not do anything. The browser console told me:

Mixed Content: The page at 'https://bla.com' was loaded over HTTPS, but requested an insecure resource 'http://bla.com/something'. This request has been blocked; the content must be served over HTTPS.

The site is reachable via https only.

The site was running behind a reverse proxy which proxied all https requests to the real server using http, because proxy-server traffic happens in a DMZ anyways.

TYPO3 seems generate some URLs based on the request url. And the browser complains at mixed (http) reqests that are handled via Javascript.

I modified the proxy config to pass all https requests via https and all is fine.