Price changes by itself in the order

[cnishop]

Hello everyone,

we have a problem with orders since we upgraded to version 1.7.7.7
Practical example:
customer XY buys a computer for € 500.
After a few days we update the price list of the computers and automatically also the order already placed by the customer XY changes price.
In fact, in the order appears the writing in red where it warns that the customer has paid € 500 instead of € 510.
How is such a thing possible?
I thank everyone in advance.

Edited August 27, 2021 by cnishop (see edit history)