here in this photo you can see that the texts are not appearing correctly, they are behind the page. And the scrollbar appears. Another thing that is happening is that it is not showing all the items that are in the repeater group.
Try changing the RG container layout to column, then adding a row container inside it - I had this issue a while ago when the new responsive engine was still in Beta - it seemed certain RGs (especially those in Reusable Elements) didn’t like Row container layouts - but I almost always put a group inside the RG cell so it didn’t really matter, and I haven’t seen the issue in a while, so assumed it had been fixed in the main release…
But changing the RG layout to column should fix it (it did for me) - so give it a try…
I can’t answer why only some items are showing in the RG, other than to suggest checking your privacy rules and search constraints…