I’m waiting on Glide Support ticket to update me what they think had happened. But we had to try plenty of things to get the app working again. Our Google Sheet is updated from Airtable every time we get orders. So multiple parties are updating the sheet at same time. This is what i think is a bit of risk.
We deleted many rows make life easier to check. especially those related to processed orders. we deleted duplicates created by Airtable and all empty rows after the last row. and deleted any gaps i found in all sheets between rows. These are the main things we did (Google Sheet wise) which I believe returned the sync between Glide and Google Sheets.
Waiting on Glide to let me know whether that helped or there were other internal issues happening.