If a computer that you need to work on shows that it is on Ninja, but does not have the TeamViewer icon, then TeamViewer needs to be fixed and Ninja needs to be restarted.  To do this, run the following scripts in order.  1.  TV Remote.  2.  NinjaRMM Agent Restart.  Once done, you should see the TeamViewer icon in Ninja and be able to TeamViewer in.