ERR_CONNECTION_TIMED_OUT with 50Mbps download speed

CesiumJS
1

I should realize a reliable application with Cesium.
My internet connection is around 50Mbps download speed, but despite this I often get “ERR_CONNECTION_TIMED_OUT” on all the imagery tiles (I’m using Bing maps).
http://alicevr.it/error.jpg

2

Does this consistently happen? Or does it go away when you refresh?

Does this happen with any other imagery providers for you?