In the Network Map a red diamond appears next to the three member servers in the Virtual Server's pool. The nodes in the pool each show a green circle. What is the most likely reason for this scenario

Disabling a health monitor causes pool members to display a blue square representing an unchecked/unknown state, not a red diamond from a failed check.

Manually disabling pool members via the BIG-IP UI marks them with a black circle indicating an administratively disabled state, not a red diamond.

If the physical servers were powered off, the node IP would be unreachable and both the node and pool member would display red, not just the pool member.

Node health is evaluated at the IP layer, so a green circle confirms the server's IP address is reachable via ICMP or similar checks. A red diamond on pool members indicates that the specific service port or application is not responding to the health monitor, which occurs when the service process has stopped while the host OS remains online. This separation between node-level and service-level monitoring is a core BIG-IP status distinction.