Thank you for the proper log-in and FTP information, I needed both in this case to solve this issue.
The problem was related to how product variation translations are stored. It might have changed recently after of the new woocommerce release, as the variation translations are not stored (instead the product translation is used obviously), but the search was trying to find their translated versions, due to an error in it's code.
I have made a correction in the plugin code, so if a variation is detected, then the parent product translation is checked instead. Now it should return the correct items.
I will make sure to include this fix in the upcoming release, so you won't have to worry about it after an update.Best,
If you like my products, don't forget to rate them on codecanyon :)