Apologies, my MQTT client I used for testing was indeed pointing to croft.thethings.girovito.nl. I also checked TTNmapper and I suspect this is also using the old backend. @jpmeijers: any chance you will make the MQTT server (plus username/password) configurable in a new version soon? It seems this is required to keep using TTNmapper on the new backend?
I was not aware there is a new public web API on the new staging platform. Where can we find it?