I would strongly suggest you to disconnect your Robot and let your Studio update to the latest 2019.4.0 version.
See here on the steps:
(you don’t have to do the Beta, but you do need to follow the steps to allow your Studio to update)
I created a new tenant/account and setup the queues again, it worked. Am currently using the trail version. Can I use the existing license code to upgrade new tenant/account?
I your question is whether you can update your UiPath components (Studio, Robot, Orchestrator) with the same license code, the answer is yes