Random Code getting pulled In Order Notes

[VibhasDudeja]

Hey Guys,

Need your help here, pleasee.
On our Shopify store, whenever a product is added to the cart, a random code is pulled in the order notes section, which is visible to the customer. 
Firstly, i thought its the theme issue, so i contacted the archetypethemes as we use Impulse. They happened to look into this for more than a week, couldn't find the root cause, but finally ended up installing the Dawn theme on the store's theme library, understanding its happening there too. 
So basically its not a theme issues.

Now i have been in touch with the shopify support, but there are not able to find the root cause either. 
Can someone please help me here?