Sometimes comma(,) does not work in formula (I am not sure but it is based on something language or regional settings on your site). So in that case use semicolon(;) instead of comma(,).
Try using this:
Calculated columns cannot be shown on list forms using out of the box capabilities.
You need to customize the list form using Power Apps, reproduce the calculated column value logic using Power apps formulas & show the calculated value on list form using label control.
It's a known limitation of SharePoint. We cannot use file name in calculated column formula.
There is a SharePoint UserVoice for this. You can vote here: Use filename in calculated field
Create a new text field & populate its value using workflow on item creation/update. Hide this field from property forms.
Use workflow to updated the Title ...