Export product function stoped working for a particular category

Hi!
I used default Woo export and import function to update my products.
But the export function stopped working when I select product with variations and a particular category.
First I had 8 products with average of 70 variations per product. Then I imported 9 new products and again with average of 70 variations per product. During the product import I accidentally imported them twice (second time was in order to update the description), so I had to delete the secondly imported products. Then I imported the variations. Now I am not able to export the products only from this category. The function just hangs. I gave it more than 12 hours without any result.

I am able to export products with variations from other categories.
Also I am able to export all products with variations for less then 3 seconds.
But I am not able to export the products from that particular category.

Please, help me troubleshoot and resolve this issue.