I tried it (both permissions and the ID3 Tags) but I got the same result.
One thing I did notice is a slight change in the way Music exports to Unicode TXT from the laptop and from the Mini. The Mini's file seems to have less columns:
1 song from the laptop's TXT file:
Mamma Mia ABBA The Ultimate Collection (CD 1) Pop 8584840 214 7 1993 13/1/17 19:09 12/4/21 20:26 320 44100 Archivo de audio MPEG Music For All The World 1 20/4/21 10:41 Copia seguridad MUSICA y DOCUMENTALES /MUSICA/ABBA/CD 1/ABBA - The Ultimate Collection (CD 1) - 07 - Mamma Mia.mp3
Same song from the Mini's TXT file:
Mamma Mia ABBA The Ultimate Collection (CD 1) Pop 8593205 214 7 1993 22/4/21 13:17 22/4/21 13:30 320 44100 Archivo de audio MPEG Music For All The World Copia seguridad MUSICA y DOCUMENTALES /MUSICA/ABBA/CD 1/ABBA - The Ultimate Collection (CD 1) - 07 - Mamma Mia.mp3
The "Copia seguridad MUSICA y DOCUMENTALES" is the name of the external volume that contains the music.