from 1.105.1 to 1.106 there is a clear regression in something. A tab with complex scene with entities using Cesium 1.106 and later will stop responding and time out. In 1.105.1 there is no problem
I am still looking for a simple reproducible case for Sandcastle but it’s very clear effect.
EDIT: reproduced in Sandcastle, now:
(zoom a bit in and out, the tab will become unresponsive)