Product date is updated when an order is placed

Hi,

I found another trouble with modified date – in product it changes to a current date when a new order is placed – but I need it to stay the same.
When I comment out these lines in update function in WC_Product_Data_Store_CPT class, it works – but it is not a solution ??

‘postt_modified’ => current_time( ‘mysql’ ),
‘post_modified_gmt’ => current_time( ‘mysql’, 1 ),

Could you help me with this isssue, please?
Thanks a lot ??