[CGF-House]

I got last week my new fire HD 8 (8th generation) and transferred all my books from calibre (around 5000) to it. Normally I have it sorted by newest/oldest on the fire under books and also in the collections.
To be sure, that all books are in collections and are really all transferred, I sorted it alphabetical and I found out, that older books (from beginning 2018 and older) are sorted like following: Title: A Material World book 1 is under 'M' and the newest book in the series Book 4 (and the German translations) are under letter 'A'.
Same with 'the' some are under 'T' and some are under the letter of the main word.
I want all under the first letter of the title.
In calibre is correct sorted.
title_series_sorting = 'strictly_alphabetic'
save_template_title_series_sorting = 'strictly_alphabetic'
per_language_title_sort_articles = {'eng': ('A\\s+', 'The\\s+', 'An\\s+'), 'deu': ('Der\\s+', 'Die\\s+', 'Das\\s+', 'Den\\s+', 'Ein\\s+', 'Eine\\s+', 'Einen\\s+', 'Dem\\s+', 'Des\\s+', 'Einem\\s+', 'Eines\\s+'), 'spa': ('El\\s+', 'La\\s+', 'Lo\\s+', 'Los\\s+', 'Las\\s+', 'Un\\s+', 'Una\\s+', 'Unos\\s+', 'Unas\\s+')} (I only need English, German and Spanish)
Metadata: any format - MTP_Device (I don't know, why it shows this with my fire) - {series} {series_index:0>2s||} - {title} - title

Where is my missing click, so that I have ALL books with articles under the first letter at the fire?