Rancher networking between namespaces

Hi, I want to set up the network in order to be able to access pods between projects.
I’ve set up rancher a while ago with rke, with the default network. Later I found out that it didn’t work for networking between projects, so I used rke to update it to flannel, but I still can’t connect to pods in other projects. Is there something I can do without deleting the cluster and setting it back again ?