Hi,
I have no idea what is Revit and I never saw and even heard about the program from screenshots, but I have a guess. Each record has ID, you can see it in the hyperlink when clicking on it, or retrieve by formula field RECORD_ID(). It looks like 'recXYZxyz...', 'rec'+14 random chars, letters in upper/lower case and numbers.
When you sync Airtable base to outer source (I used Excel to draw some graphs which were impossiible to draw in AT on that moment in time), record_id extracted as the primary field in you table, even if it not displayed in AT base.
Based on your values, I suppose that it sorts your records by record_id. Third row, 'rec2VJ..... ' seems to be first in sort order.