1) First of all try to get the Array of items with "
Document.getElementsByClassName()
"
Then it will pull all the items with that class name.
2) After adding the row dynamically, try to view the page source and check whether that tag contains specific class name that you are trying to pull.
3) Before looping the array. try to check the lenght of array, so that you will get idea whether that all row items are present or not