HTTPS monitor with headers Content-type.

Deepak_Kumar2  - Check if your need useragent header as mentioned in https://support.f5.com/csp/article/K65151034.  Check if you are using username apitest in the monitor.  Enable monitor logging under pool member and you can check the logs.

I would suggest, refer to standard Cisco ISR deployment guide with F5 and use the monitor mentioned there. I don't see PUT monitor is mentioned in the doc. 

https://community.cisco.com/t5/security-documents/how-to-cisco-amp-f5-deployment-guide-ise-load-balancing-using/ta-p/3631159/page/2