Add Row Shortcut When Hovering Between Two Row Numbers Is Causing Unintended Rows To Be Added

When hovering between two row numbers, the cursor changes to a pointer hand and green circles appear above and below the line. If you hover on a green circle it turns to a plus sign that when clicked adds a new row. What is this new feature and how do I turn it off? It is causing unintended rows to be added to a spreadsheet that shouldn't be modified. This is occurring in Excel Online using Chrome.