I'm glad to hear that your client has you on their side to help with their QuickBooks Online account. It sounds like you have a sharp eye for detail and are dedicated to making sure their books are in balance. It's important to me that the program is working the way it should so that you can have confidence in the way you're resolving issues in your client's books.
Deleting and voiding transactions are a similar process, with one purging the transaction from the books completely (deleting) and the other keeping the zeroed out copy for the records (voiding). In both cases, the program should adjust the numbers to match the zeroing out of the funds. When you say it goes back to the earlier numbers after a refresh, I'm guessing you mean that the program's calculations once again include the amounts you've deleted after refreshing. If that's the case, the first thing to do is troubleshoot.
To start, make sure you're taking the correct steps in QuickBooks Online to complete these actions. The Void or delete transactions in QuickBooks Online outlines how to do each of these tasks, so I encourage you to verify against that. If those are the steps you're taking, I recommend checking the QuickBooks Online audit log to see if the program is registering the activity. The audit log is a great tool for seeing who is completing which tasks in the books.
The next thing to do is tackle potential cache, browser, app, or Internet issues. Since QuickBooks Online works in the cloud, it can sometimes hang onto data for longer than it should. Taking the steps below ensures that it's not temporary Internet files causing the problem when you're reviewing the numbers in the program, so please give these a shot. Feel free to stop when you come to one that has resolved the issue.
If your numbers still see off, some more details about the situation will help. You're welcome to respond on this thread to let me know whether these steps made a difference and, if not, whatever other details you can share about the situation.
In the event you need to share any account-sensitive information or you'd prefer to work with someone from our support team one-on-one, I invite you to use one of the following methods to get in touch.
Schedule a Callback or Chat: click (?)Help in the upper right > type and enter "Contact support" into the QB Assistant > click Contact Us > explain your situation > click Let's Talk > choose Get a callback or Start a Chat. Support is available from Monday to Friday between 9 a.m. and 8 p.m. ET.
These options will allow you to securely connect with support to share information that you don't want shared in a public forum like the QuickBooks Community.
Don't be afraid to reach out again. I hope you have a great weekend!
Thanks for letting me know. As I mentioned, you're welcome to share more details here to get help via the Community forum, or you can choose one of the contact options I shared to connect with support outside of Community. Whichever you choose, the QuickBooks Team is here to help!