Figured it out and keeping this post for those of us learning for the first time - the secret trick is to click OK on the simulator and Cancel in Xojo, then DO NOT CLOSE the simulator… click and stay clicked on the app and click Remove App and then click Delete option when such shows… then go back to Xojo and click Run.
Each time you Run, before you Run, you have to delete the app from the simulator. Keep the simulator OPEN and running to avoid painfully long boot process.