HTTPS Monitor: JSON File behind login page

Can you open the webserver & check the htaccess file to know what type of authentication is configured. If its a simple BASIC authorization, you can check the https monitor behavior via openssl itself.

Also you can still turn on the monitor logging & see what happens for every monitor interval. Check the monitor log file in /var/log/monitors/.

Also I have read in an article that double CR/LF could cause issues on authentication headers.

So in your send string, do not give the closing double CR/LF & see how it behaves.

Refer this article - https://support.f5.com/csp/article/K54561004 - Quoted the point.

Unlike other HTTP monitor send strings, an NTLM or Basic Authentication monitor should not include a closing double CR/LF sequence. When NTLM/NTLMv2 is enabled by adding a Username and Password to the monitor configuration, the BIG-IP system appends the Authorization header and a double CR/LF sequence after the last character in the Send string.

Please keep us posted.