Format number in the form with thousand separator

Hello,

In my app I have a gallery with several items. On the second screen I have a form that shows the item selected from the gallery.

In the form there are several text input fields formatted as number. After entering the value in the input field, I would like to have this value formatted with thousands separators.

So I inserted this in the On change property of the text input field DataCardValue:

Set(varNumber2,Value(Self.Text))
 
And this into Default property of the text input field DataCardValue:
 
Text(varNumber2, "#,#")
 
This works only partially, because the problem begins when I select another item from the gallery - the values entered for the previous item remain in the fields and if I do not change them everytime I edit the item, I would have all the values for all the items the same.
 
Could you please advise how to change the formulas so it shows values for each item correctly and formatted with thousand separators?
 
Thank you very much in advance.