recording direct from bank account online payments payments

Desktop QuickBooks does not prohibit alphanumeric check numbers. I have posted checks numbered "ACH" and "epay" since I began 20 years ago. And I just tested combinations such as "test123" as well as "test-123" to see if combinations and/or special characters are allowed and find no restrictions. 

I even checked preferences and there is no setting that changes what can be entered 

Some of our locations have that problem.  We're just starting with this software, and some of us can use "DD" or "online" for a check number, and some locations are told that the check number has to be numeric.  What is happening?

I know this hasn't been an easy process for you, @WandaT. 

This isn't the kind of service we want you to experience with your support.

As mentioned above, QuickBooks Desktop QuickBooks does not prohibit alphanumeric check numbers. 

QuickBooks has an option that allows you to assign one check number and the rest of the sequence follows. Since the issue is with the numbers not staying on the transaction, let’s perform some basic troubleshooting to fix it.

There’s possible data damage on the company file causing unexpected behavior when printing checks.  Resolve it by running the Verify and Rebuild Data Utility Tool.

Make sure to create a backup to avoid any accidental data loss. Then, perform the steps below:

1. Go to the File menu.
2. Select Utilities, then Rebuild Data.
3. Click OK on the QuickBooks Information window. 
4. Follow the prompt to save a backup.
5. Hit OK when you see Rebuild has completed.

Once done, follow the same steps except select verify instead of rebuild. Here are screenshots from steps 1-3 for visual reference: 

Check out this article for more information: Resolve data damage on your company file. In the same link, you’ll find other data damage troubleshooting steps for Windows.

For further guidance, please see this article: Fix data damage on your QuickBooks Desktop company file.

Meanwhile, I'll be adding this resource in case you've got other QuickBooks concerns such as setting up payments, managing your income and expenses, running reports, etc. Please refer to this article for more details: Community help articles.

If you have any other questions or concerns, feel free to post them below. Thank you for your time and have a nice day.