All users have been added accurately, but when I try to run a report by name, one user does not appear in the list, it shows only when I run the report for all sales reps

Glad to see you here in the Community, @konstantincra. Allow me to share some details about a user not showing in a report in QuickBooks Online.

When running reports in QBO, ensure that the user is active to show their name. Alternatively, you can modify the reporting period to view the user in a specific date range.

Here’s how:

1. Go to the Reports menu at the left pane.
2. Select the report you want to run.
3. Modify the report period located on the upper left corner.
4. Then, click Run Report when done.
   
   

Otherwise, there are times that an issue like this occurs when we encounter a browser-related issue. We can fix this by running some basic troubleshooting steps.

I suggest performing the steps through a private window. It's the best place to check browser-related issues while working with QuickBooks. To save you time, use either of these keyboard shortcuts:

• Google Chrome: Ctrl + Shift + N
• Safari 11 or newer: ⌘ + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Microsoft Edge: Ctrl + Shift + P

 
 If it works fine, you can go back to your original browser and clear its cache to start fresh. You can also use another supported and up-to-date browser

 to narrow down the result.

In addition, I've got this helpful resource to guide you further on how to run reports in QBO.

Also, check out this link about memorizing your reports to save its current customization settings.

Get back to me here if you have further questions about the information above. I'd be more than happy to answer it for you. Have a nice day.