DS2019 FIT zoom makes image disappear

Hi, I am new to DS2019,
I am just trying out the commands and when I apply the FIT zoom to an .dwg drawing (to a large topo map ) the whole drawing disappears....and don't understand why nor I know how to make it reappear again (unless I undo the command)

I tried the same zoom command with a simpler drawing, like a rectangle, and it seems to work well

Can anyone explain what is the right way of using this command?