MCS catalog can be updated with a new master image with no errors. Howver when the VMs are rebooted from the DAAS console the VMS are not updated with the new image.

The Catalog was created as a Persistent catalog .  "Save Changes" was selected for Desktop Experience when Catalog was created.

To verify if a catalog is persistent check the "User Changes" field . A persistent atalog will show "On Local"

If it is desired that fhe VMs in a persistent catalog use a new master image then the VMs can be deleted and then recreated . The new VMs will then  point to the new image .

Alternatively recreate the catalog as no-persistent .

Problem Cause

The back end logs show that CleanOnBoot is set to false

-CleanOnBoot
Indicates whether the VMs created from this provisioning scheme are reset to their initial condition each time they are started.

https://developer-docs.citrix.com/en-us/citrix-virtual-apps-desktops-sdk/2311/MachineCreation/New-ProvScheme.html

As a result the VM is not reset and stays presistent  after a reboot from the DAAS Console .