Looks like this will finally be fixed in 5.3.
Epic has checked in a fix to Github.
https://github.com/EpicGames/UnrealEngine/commit/f996307f1a02a4d695ff82a8cfa34dc096991ed2?diff=split
I’ve tested it and can confirm that it works. You’ll need to build your own copy of the Apple ARkit Plugin. But other than that, the fix is pretty simple.
-e