I thought the issue might be related to browser, as it works for you, so I tried Chrome. But no luck.
These are the steps I am following:
Components > medialibrary > media > New
Media Type = video
VideoID = <Random number>
ASIN = <Random number>
Language = English
Joomla Language = English (UK)
Category = video
Fetch Information = On your own
Save & Close/apply
Error: The page at <website> says:
[OK]
When I click OK the browser (Chrome) displays:
Confirm Form Resubmission
Details
When I click Details, the details display as: This webpage requires data that you entered earlier in order to be properly displayed. You can send this data again, but by doing so you will repeat any action this page previously performed.
Reload this webpage
Press the reload button to resubmit the data needed to load the page.
Error code: ERR_CACHE_MISS
Logged
The administrator has disabled public write access.