The instance must be stopped before changing the instance type. You need to right-click to instance select Instance settings and Change instance type.
You need to be careful when changing the instance. Some instances only support ENA (TB Trk#24792), so for the time being if you upgrade the instance to ENA supported instance SBC will not work and we are working on this to make it support accordingly.
After changing and starting the instance tbrouter is giving following error;
**** Host reboot is required to fully activate the firewall ****
Rebooting the ProSBC solves this issue.