GTM Continues to Resolve (Generic Host) IP's From Pools That Are Down

Hi, 

I understand you have defined the "Global Availability" method in WideIP level, 

so I understand that PROD pool is trying to do a "Fallback" once it has no members available.

This fallback option is usually defined as "Return to DNS" by default.

Try to change this to "None" in this PROD pool and let us know if it works as expected.

Kind Regards.