Validation server logs indicate an error 18530 occured at VSValidationserver.
ERROR "2020-20-20 00:00:00.000 GMT0000" 10.10.10.1 Citrix_RADIUS:1812 0 0 "text=VSValidationEngineProcessRequest() -- Authentication Failed for user [<User-Name>].
VIP Enterprise Gateway
The NAS or Load balancer is pinging the validation server with an invalid or malformed RADIUS request.
The health check or heartbeat from the source must be formatted as a valid RADIUS request. If valid, the VIP Enterprise Gateway can be configured to accept Load Balancer checks. Refer to VIP Enterprise Gateway Load Balancer health check configuration for more detailed explanation about this issue and resolution.