Making some testing, I found that decreasing the number of the question that determine the maximum number of items of the repeated group, the last items are deleted, but I didn’t find a way to delete a specific item, or a way to change the sort order of the items.
@mgiacomozzirc, yes sometimes, you may have unnecessary records within a submission. You could delete them from the server. Here are the steps to edit/delete a record from the repeat group:
Under the DATA>Table View, click the pencil like edit icon as shown in the image below:
Continuing the investigation, I think that the issue occurs when the repeated group item’s repetitions are determined by another question (through the repeat_count). Indeed, I tried another survey without this property and it works exactly as you describe.