Hey there, 01sue.
Thanks for reaching out here in the Community for support. I want to make sure you're able to see the memo line when entering a Sales Receipt.
As an initial troubleshooting step, I recommend clearing the cache in your internet browser. The cache can sometimes become bogged down with historical data, which can potentially cause viewing errors in QuickBooks Online. This article will walk you through the steps to clear the cache, depending on which browser you're using:https://quickbooks.intuit.com/community/Getting-Started/How-do-I-clear-my-browser-cache-and-temporar....
I wish you and your company the best of luck. Feel free to leave a comment and let me know how things look after giving this a try.