Appsheet not calculating columns separated by blank rows

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Hi Community
Need a little help here.

I’m trying to make an app for e-commerce.
There are 2 tables ORDERS and SALES, basically ORDERS Table is the summary of SALES Table. In 1 column of the ORDERS table, i am using an app formula as below :

SUM( Select( Sales[Margin] ; [Order ID] = [_THISROW].[Order ID] ))

Works most of the time, but when i delete any input in the app, it messes up the calculation. I see whenever i delete something, appsheet doesn’t delete the row in the spreadsheet, it leaves an empty row instead. So the formula above doesn’t calculate the separated rows even though it has the same Order ID.

Is there any way to make this formula works the way i need it to be?
Thanks to anyone answering