to elaborate on Anthony's response, you can refer to these links:
-> section "How can I move a FortiGate from account A to account B in the same region?"
-> "To move a FortiGate/FortiWifi deployed to FortiGate Cloud to another account:
To move a FortiGate/FortiWifi that is already deployed to FortiGate Cloud to another account and retain its historical data, you must follow these instructions.[...]"
Please note that historical (log) data is only retained if you move a FortiGate between accounts in the same Region (Europe OR Global), but the data is lost if you move the FortiGate from one region to another (from Europe TO Global or vice-versa).
+++ Divide by Cucumber Error. Please Reinstall Universe and Reboot +++