Thanks for visiting us again here in the Community forum, M for TF.

QuickBooks Online release and updated some features in which one of those is the Account details section. Right now, it's been changed to Category details.  For your visual guide, you can check below screenshot:

For you to change the affected account, be sure to go to the Category column under the Category details section. Then, you can continue to follow the steps above provided by my colleague JamesDuanT.

The article below provide you more insights about editing an expense transaction: 

Enter, edit, or delete expenses in QuickBooks Online.

Please let me know how it goes by clicking the Reply button below. I'm always here to help if you have any other concerns. Have a great day!