The customer has a set of RDP servers that are fronted by a jump server or load balancer.
When the connection is made by the agent an error us recorded with the first 8-bit of the ip address in decimal form:
missing application called "172"
For example the error above occured because the connection was going to a server on a 172.16.0.0/12 segment.
ZTNA and RDP load balanced server farm
The load-balancing / connection broker for RDP are not supported and cannot be used as destination RDP servers (because they are not RDP servers).
RDP applications can point to individual RDP servers but not to load-balancer / farm front-ends or jump servers.