Please check inside the loop you might have put some condition that is not creating a fixed number of iterations, or the loop is continuing infinitely. It is also possible that You may have used continue event after some condition which is always getting true.
Hope it helps!
If it does not help, can you be more specific with a picture?
Check if in your microflow loop has some refresh in client in change objects. Remove Refresh in client and also do check the conditions of the loop whether properly set.