fillable PDF, with two text boxes linked

I created a fillable PDF, with two text boxes linked by this code:

var t1=this.getField ("RennenVoorDeGeit1"); if (event.fieldFull) { getField("RennenVoorDeGeit2").setFocus(); }

Now when I type a text within acrobat the text does move to column 2 but when I copy a text from microsoft word it no longer works. Anyone have an idea what is going wrong?

Using Acrobat 2024

Here is the PDF file.