Please check if vRNI is receiving flow data from ESXi hosts. you may run a query "flows" and check if it returns any results.
If not, pleases check if you have enabled IPFIX Add vCenter Server
Sr.Cloud Solutions Architect
VCP 3/4/5, VCAP-CIA, VCAP-DCA.CloudU
Sr.MTS. vRealize Network Insight.
I had this happen the other day when we were redeploying vrni a second time, with new IPs. Adding the datasource and enabling IP fix never changed the actual collector IPs in the VDS. As mentioned above, check the Netflow settings in the VDS and make sure it's pointing to the correct IP.