The pool member is markedDOWNbecause it is monitored bymultiple health monitors, specifically anHTTPmonitor and anHTTP/2monitor. The status message clearly shows that theHTTP monitor is UP, while theHTTP/2 monitor is DOWN. In BIG-IP, when multiple monitors are assigned to a pool member, the default behavior isAND logic, meaningall assigned monitors must succeedfor the pool member to be considered healthy.

In this scenario, the server is responding successfully to standard HTTP (likely HTTP/1.1) requests but does not support or respond correctly to HTTP/2 requests. As a result, the HTTP/2 monitor fails, which causes the overall monitor status to beDOWN, even though HTTP traffic itself is working.

This behavior is expected and documented in BIG-IP monitoring logic. Unless the monitor rule is explicitly changed to“at least one of”, a single failing monitor will mark the pool member down. Therefore, the correct conclusion is that the pool member isonly serving HTTP traffic, not HTTP/2.

The resolution would be to either remove the HTTP/2 monitor, correct the application to support HTTP/2, or adjust the monitor rule to match the intended health-check logic.