F5 Http Health Monitor check truncates response

I configured a http health check on F5 and the request gets a rather large response, but if I perform the request manually from the browser it works.

But on F5, I configured the "Receive String" to check for the contents in the end of the response, and the health check is failing.

I used tcpdump to inspect the traffic on the target I could confirm that the response is truncated (F5 closes the connection before it ends).

Is that a bug? Or is it an expected behavior?

Thank you