BIG-IQ 5.2.0 HA Pair, Login Using RADIUS Auth Provider

Hi, We set up Auth Provider for authentication and authorization using RADIUS server. The BIG IQ version is 5.2.0 and in the primary, we can login using account from RADIUS auth provider. Because the BIG-IQ is HA pair, so the configuration from primary is synced to secondary. When we open secondary BIG-IQ, there is RADIUS auth provider selection in login page. But when login using RADIUS server account in secondary BIG-IQ, there is error:

 

What does the error mean? Does anyone can explain to me?

 

Thank you