So I have a centered text box 'Some text' at coordinates X 6.0 Y 3.0.  If I edit it inline e.g. 'Some text1' the X and Y coordinates don't change.much X 5.8 Y 3.0

But if I edit the text in 'text and font', text and hit apply the whole text jumps right a huge distance  to X 9.8 Y 3.0 and I see it is now left justified.  If I change the text box back to centered it doesn't move it back.

What am I doing wrong / how to fix?

Thanks

Sorry, I can't reproduce the problem. When I click [Apply], the updated text remains centre-justified and the text anchor doesn't move. Can you upload a misbehaving file for investigation?

I've hopefully provided a simple example file.  Try editing 'Text line 2' to e.g. 'Text line 22' and see how the text box jumps to the right after hitting apply. 

I am using Inkscape v1.4 on Windows 11.  

Thanks

I have in part replicated your experience. The problem seems to be related to the diamond anchor point being moved some distance to the right of the text.

Re-aligning the text to align-right will cause it to jump to the right and then align-center will not return to its original position. You can see some of my experimenting in the attached text_issue_edited.svg.