Thanks, we’re submitting an update to fix this shortly - possibly the weirdest bug we’ve encountered in Pleco’s history, we traced it back to an issue in the latest version of Apple’s LLVM *compiler* (the program that turns source code into a computer program).
Essentially, one of the many things compilers do to make programs run faster is to rearrange the order of operations to maximize their use of processor resources (have as many parts of the processor chugging away at once) - this is done very conservatively / carefully, though, and never unless the compiler is absolutely sure it won't screw things up, but in this particular case the compiler is rearranging some things it shouldn't be.
Looking forward to filing the bug report on this with Apple, actually, as it's rare that one finds bugs at such a low level and the people who deal with them are frankly way better programmers than I'll ever be
