Inconsistent group spacing in DataGrid

[mjazd]

Describe the bug

When using groups in DataGrid a column is added for indentation. When displaying less than 26 rows this column is not present.

To Reproduce

1. Run minimal reproduction: https://github.com/mjazd/DataGridSpacingBug
2. Put 0 in the TextBox and hit Filter, now the indentation is missing.
3. Put any number smaller than 26 in the TextBox and hit Filter, the indentation is still missing.

The number in the TextBox limits the number of lines shown in the DataGrid. If going straight from a number larger than 25 to a smaller number then the indentation is still present. The indentation is missing after sequence: (>25) -> 0 -> (<26)

Expected behavior

No response

Avalonia version

11.2.3

OS

Windows

Additional context

No response

[maxkatz6]

IIRC, this extra column is reserved for row header. But that's weird its visibility depends on rows count.

[mjazd]

This column is different from the one for the row header. If I populate the row header it looks like this: