Hi @Olivia Aiello ,
Did you check different columns when creating different views?
Please go to List settings>Views, select the view you want and check the columns you want to display. If not, there will be no unchecked data in this view. Per my understanding, this is the issue you mentioned that the data is not synchronized.
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Let me show the difference:
All items view:
In testview when I uncheck columns:
Reference:
Create, change, or delete a view of a list or library
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