Thanks AreDigg. The script works again.
There is something that maybe a general dilemma in getting composer and lyricist.
I don't know how the information on the Apple-site is structured, i.e. if they distinguish between both, but I noticed that with your script both seem to be always combined in the field COMPOSER.
@vikaesar has made a Deezer script:
https://community.mp3tag.de/t/ws-deezer/45537
and distinguishes between COMPOSER and LYRICIST. Where the websource is maybe not so clear he seems to use INVOLVEDPEOPLE to combine these.