Why does the customer cart change at checkout randomly?

Our customer’s cart will convert to a different order when they reach checkout. Does anyone else have this issue or how to fix it? It is at random. Different product, quantity, and total amount.

There hasn’t been any changes to our coding or haven’t installed any new apps recently.

Hello @rbozeman !
Hope you are doing well.

Could you please share some more details about the issue you are getting? So that I can check and get back to you.