category not functioning

hi, i checked in all faqs and any suggestion found did not work for me.
i am using the last postie version with the last WP version. i put the name of category in the subject, or id, all the format suggested but postie still putting the article send in uncategorized. the categories used already exists.
this is the last tentatives:

product//[lavorare-oggi] my article product title
[lavorare-oggi] my article product title
[lavorare-oggi]: my article product title
category lavorare-oggi: my article product title

and the same with category id, with and without [], -, :
and the same with or without the word “category”
thanks
Giuliano

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