To resolve this issue, it is necessary to configure Citrix XenApp to return fully qualified domain names (FQDNs) instead of IPv4 addresses. This will allow the DirectAccess DNS64 service to function properly and return an IPv6 address to the client, restoring connectivity to XenApp resources.
To configure Citrix XenApp to return FQDNs, refer to one of the following Citrix technical support articles for more information.
CTX128436 – How to Enable DNS Address Resolution in XenApp 6.x
CTX135250 – How to Enable DNS Address Resolution in XenDesktop 7.x