I am not quite sure it this has something to do with the fact that the db server is of cloud-infra mode instead of full-stack. (I have many POCs before in other client sites, where the db servers are installed with cloud-infra mode. But too bad I can't remember if any of this happened for them)
But from I recalled, if I am correct, whether or not it is cloud-infra or full-stack in db server, the purepath should show the name of the call/request to the db server instead of 'request to unmonitored host'
Anyone can verify this/correct me if I am wrong? or has some idea of what's going on here?
The call is of a Web Request type. It's not calling a database service. Or at least not directly. That's why you will need to do a full-stack monitoring on the host and not the infrastructure only. Try enabling the full stack monitoring (and restart processes on target host) if this makes any difference.