Möglicherweise ist ja auch nicht die Renderengine kaputt sondern der Test schlicht veraltet.
Tatsache!
Zitat:
WaSP operations declared success in 2013, and the Acid Tests are correspondingly no longer being maintained. Acid3, in particular, contains some controversial tests and no longer reflects the consensus of the Web standards it purports to test, especially when it comes to issues affecting mobile browsers. The tests remain available for historical purposes and for use by browser vendors. It would be inappropriate, however, to use them as part of a certification process, especially for mobile browsers.
Quelle:acidtests.org