Safari stops playing Amazon video content - Silverlight IS installed
Recently, I'd been using Google Chrome for everything but suddenly it went wonky and would'n open known websites (Apple.com Google.com) so I decided to fall back to using Safari 12.1 b(13607.1.40.1.5) but when I go to Amazon to view Amazon video content I KNOW I have, I get an "unsupported plugin" message from Safari. I know that Amazon's video content runs on Silverlight - and that's already installed. Any ideas what's up?
iMac 21.5", macOS 10.13