Confirm exchange rate on each foreign item? Other systems use day's historic rate. Go to the transaction details to check the exchange rate, then select Confirm."

Hello there, dean32.

I'd like to verify where you received the prompt or message so I can walk you through from there. Every time you update the exchange rate within the settings, it will not affect any previous or existing transactions, only those future ones. 

A browser-related issue might have caused an unusual response when entering and saving your transactions. You can try logging in to a private browser and then enter and save the transaction from there. If you didn't receive any prompt, you can switch back to the main browser and clear the cache. Alternatively, you can use other browsers to isolate these kinds of issues. 

Here are a few articles that you'll want to check out for more details on how multicurrency works:

• Learn about exchange rates in QuickBooks Online
• Learn about multicurrency in QuickBooks Online

Keep me posted if there's anything else that you need help with. Take care!