Hi, With the turn off the Autoplay, I solved the problem. Thanks

Assumption that I have a 100Mbps and not a slow dsl line,
I think that the problem isn’t the slow download of the file.

When I click on the URL of that video with Safari, the page is white for a log period of time, BUT if click on the same URL with Google Chrome, the page appear immediately and the video start soon.
So, I’d like the same result with Safari.

I have tested my website with the default player of WordPress and it start immediately. This is the right operation!

Why your player doesn’t start immediately?

I think you haven’t problem because you have a fiber line.
If you try with DSL connection, you discover that the page not appear until the player has a good buffer (I can see a white line run).
On other Mac with Safari appear the error and not see completely the video, but I don’t know the version of the system.
I hope I have clarified with my poor English!

Sorry, I forgot to show an example, test here:
http://hopechannel.it/sola-fide/
Thanks