Problem: You have set the promo price in the product detail page but when you add the same product in ePOS, the promo price set in product detail page is not applied.
Solution: Please make sure that you have set the min order column value to at least 1 or more in order to make promo price work correctly. Min order is the minimum number of qty when promo price is activated. If it is 0, then promo price will not be applied. You can set the min order field value from the product's detail page. (Pleas refer the image below)