What are the units in Experiment Settings / Screen?
Are you doing anything which tries to measure the screen size? I sometimes find issues where the screen size gets measured before the experiment goes full screen, which means measurements are out later.
In my Crib sheet I have:
Issue: Slider label positions don’t always match up.
Solution: Add experimentInit(); to the End Routine tab of code_JS (or possibly later if your routine containing code_JS doesn’t have a duration). Sijiazhao
Beware – this seems to rerun all Begin Experiment code, so any variables changed in the first routine may get reset.
N.B. code_JS as recommended in my crib sheet isn’t needed in 2022 versions of PsychoPy but the principle is to run the code after a second or so but before anything important has happened.