Thanks for trying the steps provided by my colleague, HowdyHowdy.

We have another troubleshooting steps to isolate why the collapse arrow is not showing on your end.

Let's run verify and rebuild data and check to see if your file is damaged. Let me guide you with these steps:

1. Click the File menu.
2. Select Utilities, and then Verify Data.
3. Select OK if it detects no error however, select Close if it finds an issue. Then, do a manual repair.

Then, let's rebuild the program. We can do this by clicking the File menu, select Utilities, and then Rebuild Data.

Afterward, let's check to see if you can now see the collapse arrow on the report.

I'll be keeping an aye for your response as to how this troubleshooting steps work on your end.