Hi,
I found the solution to my problem. It is here:
https://github.com/woocommerce/woocommerce/issues/11764
Go into your database
Find wp_usermeta
Search in the meta_key column for “manageedit-shop_ordercolumnshidden”. Check the user ID in the column left to it. If you’re having problems with your admin account, the user ID will be 1. Otherwise you should look further for the right user ID with “manageedit-shop_ordercolumnshidden”.
Click on the left on Edit and change it’s value to a:0:{}
Reload your order dashboard and you’re check-all checkbox should be there.
