Format String "$num(%track%,3) - %title%" not working

format string "$num(%track%,3) - %title%" not working

Mp3tag Support 2026.03.25

mp3tag-v3.33.1-x64 (2026.02.06)
Using Windows 11, v 25H2, OS Build 26200.8037

Most often trying to change file name using "Tag - File Name" using the format string $num(%track%,3) - %title% the result comes back as "005 - .mp3" as an example. Works some times - sometimes not.
The format string I have been using is a copy / paste so this string works AND don't work.
I have 92 albums and over 9000 files (songs). Mostly using to organize and number each album.
So far all else seems to be working as intended. I have used this successfully in over 80 albums and 8000 plus files (songs).
It has been not working both before and after other files have been renamed. Right now there are two (2) albums (144 & 22 files) I need to do and all files do play OK.
I have restarted my computer and downloaded and reinstalled several times.

New to this site for help. Been a user since 2017 (Purchased twice 2017 & 2022).
Any help would be great.

This looks like there is no data in the field TITLE.
Please try a filter to find files where that field is missing:
%title% MISSING

Then check the extended tags dialogue for such a file and see if the data for the title appears in a field with a similar name, e.g. titel.

Thank you. That was the problem.