Why does the currency change after checkout on my online store?

[pridumay]

After placing an order, customers see the price in the local currency of Shopify. at the same time, the correct currency is displayed in the shopping cart. the problem appears when the customer makes an order, then returns to the store and sees the local currency, after adding the product to the cart, the value changes again to the standard one. I recorded a screencast at the link

https://drive.google.com/file/d/160Prd-8iUsm_HXHJLP9tuJhEr1eHHWSR/view?usp=drive_link