I'm using a numeric textbox to handle a decimal value with the Format is set to "#,0" (which it needs to be since the client's specification is to have a whitespace as a decimal separator). While the entered value is less than a thousand then the entire value gets selected when tabbing into the component, but once it's large enough to display a group separator tabbing just puts the cursor at the end of the input without selecting the value.

I believe this to be a bug.