plot_scatterplot is ordering the labels wrongly

[DeLaRiva]

Hi,
I'm having troubles to get the order of a scatterplot with two numerical variables right:

I tried so many things now, I don't know where the reason is or could be. Could you please check?
The variables are definitely numeric in the data frame.

[boxuancui]

Would you mind providing a subset of reproducible example (data + code), so that I can investigate? It works fine on my end.