Like any PC, once in a while your WorkSpace need to be restarted to refresh it. Please follow below steps Workspace:
There’s 2 ways to restart WorkSpace. One, is like normal PC which id, go to Start > Select power button > Restart
or
Go to the Left top menu
Select Amazon WorkSpaces
Select Restart Workspace
Wait around 15 min and try again
Hope this will solve your issue.
Regards,