Product price note missing from random orders

Hi, I use a plugin (Woo Set Price Note) to display the price units of the products (1$/kg or 2$/unit). It works well on the website but on the orders, the price notes are sometimes not displayed and it’s totally random and not specific to the product. Customers receive random invoices with missing data. https://ibb.co/4Y3q7gg https://ibb.co/LJ0ns13 The author of the plugin does not answer my questions. I try to determine where the problem can come from but I have no idea wat can cause this kind of issues. Thank your for your help !