That sound like a browser problem to me.
Start by trying a different web browser. If you're using a Windows 10 computer, you'll have Edge available to (directly from the Start menu) together with Internet Explorer (which is under 'Windows Accessories'), as well as whatever you usually use (such as Chrome or Firefox).
If all is well when using a second browser, the problem obviously relates to the first one. In that case, return to your original browser and reset it to its 'fresh out of the box' state. (It's dead easy to do but we'll need to know which web browser you use in order to provide specific instructions for it).