Need help-the web is stuck when using Safari browser

The product we developed based on playcanvas became stuck when you open it on Safari browser.
We debugged the other browser, such as chrome and firefox, all is fine.
And the reason why it has bug on safari browser, according to our investigation, is about it’s CPU when the project on work rather than GPU. While using other browsers, it’s GPU working rather CPU.
We assume there is a code on other browsers(qq, chrome, and firefox) so that it can make GPU working, while there is no such code on Safari.

Our question is: How to fix the stuck problem on Safari when you open the product?

Link to product: