Yes, as noted above, unless you use the fsync etc. options, it is not reporting the progress of the physical write on to the USB stick. Fedora Media Writer perhaps reports progress of the physical write but we’ll have to check its sources to confirm.
So, either you use the additional flags, or just wait for the stick lights to stop showing progress. I suspect if you try to unmount it, you will get a warning that it is still being written to.