The undo and redo buttons in Studio are not trustable.
Sometimes you create a variable. I’m in the same scope. I press undo, it dissapears. I’m still in the same scope. You press redo. The variable doesn’t show up in the list anymore. I’ve checked and rechecked this a dozen times.
The arrows for “undo” and “redo” always stay “on”, even in there’s no more undo or redo actions to do. They should be greyed out when there’s nothing to do. This is a basic usability problem.
Both controls show include an arrow to display a list with the history of available “undo” and “redo” actions to avoid confussion, as every other mild serious software do.