Inventory sale amount not saved

Good day. I have downloaded the program and want to use the sales invoice items for my invoicing. Problem is that the program does not save my invoice item amount. I have tried to reinstall the program but it made no difference. Don’t know if I am doing something else wrong. Please help.

@Zinia, maybe you are not entering the amount in the correct format. Check Preferences tab to see what number format you have set.