GMT / LTM (DC 1+ DC 2) active/standby virtual server health check fails

We have 4x virtual F5 running in 2 data centers (DC1 + DC2). The GTM config is that they are all part of the same sync-group each configured with a listener IP (self-none float).

 

For the LTM configuration, it is setup in active-standby (one pair per DC).

 

The issue that I am seeing is that when I configure a virtual server on a stand-by LTM in the DNS section, the health check fails. Even though the same virtual server is in green status on the primary LTM.

 

I am not sure if this has something to do with the fact that the LTM is in standby but from my perspective, I would like to have all 4 GTMs serving DNS requests and monitor virtual servers configured on the LTM setup in act/standby.

 

Does anyone else run in that configuration? Any advice would be appreciated it.

 

Thanks.