How to maintain aspect ratio of axis with 'PlotBoxAspectRatio'

I am trying to change the default settings for all my figures in matlab. I am struggling to maintain a square plot above all other comands.

I currently have (toy example):

set(groot,'defaultAxesXLimMode','manual')

set(groot,'defaultAxesYLimMode','manual')

set(groot,'defaultAxesDataAspectRatioMode','manual');

set(groot,'defaultAxesPlotBoxAspectRatio',[1 1 1]);

figure;

errorbar([1 2],[0.4 0.5],[0.03 0.05])

xlim([0.5 2.5])

This respects the aspect ratio of 1:1 for the x and y data, but I would like it to be 1:1 including the limits of .5 and 2.5 without having the include new data points for the x and y data.

Is there a way to do this?

NOTE I have spent a lot of time looking through questions for this, however it is the first question I have asked here so any comments on how I could ask better questions, or search for answers better are appreciated.