This. This is what hung me up for hours. The "jump brackets" can be nested and only stop when they reach their partner - not just any closing pair.
On the up side, I got to explore the rabbit hole that is "what should happen on memmory wrap-around".

Ok, I have it :) it didn't mentioned but you have to go backward to the firs bracke it means to brackeet which is a pair to actual one.

Ok I have a question about working command [ and ]
if we have list of commands ",[.[-],]"
on the second place we have this bracket "[" then on the last place we have "]". So if the last bracket we reach and we have value in memoryCell different than zero, we should go back to this mentioned first bracked on the second place in string (index 1) or to the bracket which appears first when we go backward - on the four place (index in string 3) ??

Of course, I didn't think about modulo :D now it is obvious :D thanks :D

You can use the '%' operator. Look my solution