Failed to match looping brackets properly
+++++[>++[>+++<-]<-]
Closing brackets always return to most recent opening bracket instead of the matching one, making any code with nested loops break. Better than any other brainf interface I’ve seen (even on computers), but fails at a basic level.
Note to dev- instead of storing location of most recent open bracket, push it to stack and check stack when you hit a closing bracket. If current cell value is zero, before moving on, pop from stack.