The main issues is that you are repopulating the values of the “Title” field after saving. This is removing the values. You have 2 choices here.
The first is to not populate the “title” in each row if the field already has values. You need to test the value pasted to your filter by ACF and if it already contains values then you do not run your code.
The second is to somehow loop through the existing values and repopulate the title sub field. I’m sure it’s possible, but complex, to do something like this.
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