Created attachment 198658 [details]
ZIP contains two ODS files: test.ods created in normal mode, and test_safe.ods created in safe mode.

There are a couple of images in the discussion following my investigation here:
https://ask.libreoffice.org/t/conditional-formatting-window-in-lo-24-8/116898/3

Two test files are attached: test.ods and test_safe.ods.
The first was performed in normal mode, immediately following a computer restart.  The second was performed in safe mode (radio button set to the "factory settings" option, and then hit "Continue"), immediately following the creation of test.ods.  (I closed LibreOffice in between the two tests, but did not restart the computer).

Reproduction procedure:
1. Open LibreOffice
2. Create new Calc Sheet
3. Enter random values in Column A on Sheet1.
4. Add new sheet, “Sheet2”, via the Plus sign at the bottom.
5. Enter random values in Column A on Sheet2.
6. Navigate back to Sheet1.
7. Format >> Conditional >> Manage
8. Click “Add”
9. Manually input “A:A” in the range, put the value “foo” (in quotes) in the value field, and select a style. Hit “OK”.
10. Navigate to Sheet2.
11. Repeat steps 7–9, without ever going back to Sheet1. Note that the conditional from Sheet1 was already visible in the window.


NOTE: There was also a transient bug in my general use and in my initial testing where conditional formatting for Sheet1 appeared to become also attached to Sheet2 (as if it had been CREATED on Sheet2, as well as Sheet1), but I haven't isolated or reproduced it in focused testing, so I haven't created a bug for that, yet.  I only mention it in case it brings to mind anything relevant for other testers.  If/when I'm able to consistently replicate it and rule out user error, I'll create a separate bug for it.