Sort seems not working under specific order, I do not uderstand

Attached file contains some colum.
If I try to sort ascending based on column A, table seems mixed up. Column A should contain TEXT value, instead of NUMERICAL, that is why, leading zero appended below 10
If I try to sort based on any other column, seems OK.
Effect independent from column itself, as I tried to copy content to another column with same effect.
Once I try to convert to NUMERIC value (creating a column G with formula ‘=INT(Ax)’, and sort based on column G), it works.
Original sort does not seems to be NUMERICAL neighter TEXT (01 should lead 20 for instance).
Thanks for any idea.

It sorts numerical values first, then textual. So you may easily see which of your values are texts (going below), and which are numbers (above). Or you might use View->Value Highlighting.

One hint: Use manual alignment (in your case: center) only, if you have assured the data is of the type you assumed 'em to be. Perform a CTRL+M on column A and you immediately notice the different types of your data (numerical values are right aligned, while text is left aligned).

Select data in column A, choose menu Format - Cell… - Numbers tab, and set Format code to 00: you will see 1 as 01.

Re-select the data (maybe a bug here) in column A, choose menu Data - Text to Columns…, OK: now all numbers in column A are real numbers.

Tested with LibreOffice (x86); OS: Windows 6.1.

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