Thanks for taking the time to write your concern here, @steven66.
Can you tell me what specific changes you're trying to save in your QuickBooks Online mobile app? I would also like to know if you encounter error messages when saving these changes. Any additional information will help me provide a timely resolution.
In the meantime, let me share a couple of troubleshooting steps to isolate the issue. Sometimes, we encounter unexpected behaviors like this if an app is full of cache. With this, I recommend clearing it to help refresh the app and ensure that it is updated to the latest version. Clearing the app's data can be done on the app or your phone settings. Depending on the device you're using, you can follow the steps below.
For the IOS version:
Go to the Menu icon ☰ and tap Help & Feedback.
Select Refresh Data.
Tap RefreshData then Refresh to confirm.
Go to the Menu icon, then tap More Options ⋮.
Tap Settings then Refresh Data.
Select YES to confirm.
Then, restart your device. If it didn't make any difference, let's uninstall and reinstall the mobile app to fix app-related issues.