Problem with copying and pasting text!

Hi guys

I added this plugin yesterday to my clients site, and believe it or not as i have checked this myself! when the plug is activated the client cant copy highlighted text on the shop website! she can copy and paste on other sites but for some reason this plugin makes it so that she cant copy whilst its active?

Do you have any thoughts on this?

thanks

https://www.ads-software.com/plugins/woocommerce-sequential-order-numbers/