How to reproduce:
1. Create a new Unity project
2. In the Assets folder, create a new UI Document
3. Open it in UI Builder
4. In the UI Builder Hierarchy, add a TextField and select it
5. Navigate to Attributes → Language Direction and set it to RTL
6. In the Viewport, enable the Preview mode
7. In the TextField input "testing"
8. Move the pointer in between the "n" and "g" characters
9. Press the Delete key
10. Notice how in the Viewport the character “n” was deleted first
11. Press the Delete key again
12. Observe the viewport

Actual result: You are allowed to delete the character "g" despite the cursor position indicating otherwise
Expected result: Only the letter "g" is deleted, and you cannot delete any more characters

Reproducible with: 2023.3.0b1 (a9472903d2b0), 6000.0.68f1, 6000.3.9f1, 6000.4.0b9, 6000.5.0a7
Could not test with: 2023.1.0a1, 2023.2.0a1, 2023.3.0a2 (the language direction attribute was not available in these versions)

Reproducible on: Windows 11
Not reproducible on: No other environments tested