Firefox is much slower than Chrome or Edge on some Rust document pages

I have to be clear.

When I compare the performance, I mean the time from you click on the link until the page is being functional - at least, you can click on the links. When measuring this, I count from the time I hit the "refresh" button until it stops spining.

So my measurement is
Chrome 72.0.3626.109: ~10 seconds + clash (showing the "Aw, snap" page)
Edge 42.17134.1.0: ~3 seconds
Firefox 65.01(64-bit): ~30 seconds.

Machine: Intel Core i5-8500 8GB
OS: Windows 10 version 1803 (OS build 17134.590)