No, but I'd wager that I would spend more time re-writing the app for each native language than I would finding the inconsistencies in Haxe. (And either way, each platform has its own nuances that you have to know whether or not you use Haxe.) For the record, you'd have the same issues with solutions like Xamarin. The whole thing is a trade-off, and I have a (well-supported) hypothesis that the benefits of a (semi-)shared codebase is worth the cost of learning these nuances and inconsistencies.

These languages are certainly more mature than Haxe, but I do still expect to find some bugs in their standard libraries (in performance or security).

And when you factor in third-party libraries, the answer is always "yes you do expect to encounter bugs" independent of the language. For me, programming is in great part reading and fixing other people's code, and I still think most of them are much more skilled than me.