The reason is rather simple: Your
continue statement instructs the shell to immediately skip execution to the next loop iteration.
Unfortunately you thereby skip the
((COUNT++)) part, meaning that once
COUNT reaches 5, it will never be incremented again, and the
while condition never be met, so you are stuck in an endless loop from that point onward.
If, as @steeldriver assumes, you instead wanted to break out of the loop at a
break statement would be the correct choice.
As a general remark, if you are interested in learning more on shell scripts, I would recommend GreyCat&Lhunath's Bash Guide. Also, running your scripts through
shellcheck (also available as standalone program on many OS repositories) can help identify syntax errors and the like.