As you noticed, the column does not have any option value set hence why the frontend is shwoing NULL. Can you also check what is the data type for this column ‘value’ in your catalog_product_entity_int?
Also, post update of your reindex - if any.
@asrarau Sorry for the delay.
These screenshots are after the reindex
Are you find a Solution..? I Have Magento 2.3.2 with the same problem, size attribute show null in the front page of product...