That was the problem! Is it possible to have Opera Turbo on on every site, except for this one, like an exception?

No extension, 3 plugins (Widevine Content Decryption Module, Chrome PDF Viewer and Adobe Flash Player), block ads on and Opera Turbo on.

It works in other browsers.

I have Windows 10 and Opera 39.0.2256.71 and when I try to watch a video on NHL.com, the video won't load up (a rotating circle that rotate to infinity).

https://www.nhl.com/canadiens/video/highlights-tor-4-mtl-3/t-277437414/c-44724803