Why do I have to double click to select an InlineQueryButton?

I have this menu here:

keyboard = [
    [InlineKeyboardButton("Modifica Materie", callback_data='edit_subjects'),
     InlineKeyboardButton("Modifica Voti", callback_data='edit_grades'),
     InlineKeyboardButton("Resoconto", callback_data='resume')],
    [InlineKeyboardButton("Suggerisci Modifiche!", callback_data='suggest')],
    [InlineKeyboardButton("Supporta il progetto!", callback_data='donate')],
]

menu_query_keyboard = InlineKeyboardMarkup(keyboard)

And the first two buttons are linked to MENU_QUERY_HANDLER:

EDIT_SUBJECTS_HANDLER = ConversationHandler(
    entry_points=[CallbackQueryHandler(edit_subjects.display_subjects, "edit_subjects")],
    states={
        "select_subjects": [CallbackQueryHandler(edit_subjects.select_subjects)],
        "add_subjects": [MessageHandler(filters.TEXT, edit_user_subjects)],
        "back_to_menu": [CallbackQueryHandler(back_to_menu, "menu")]
    },
    fallbacks=[],
    map_to_parent={
        END: "selector",
    }
)

EDIT_GRADES_HANDLER = ConversationHandler(
    entry_points=[CallbackQueryHandler(not_avaliable.not_avaliable, "edit_grades")],
    states={
        "back_to_menu": [CallbackQueryHandler(back_to_menu, "menu")]
    },
    fallbacks=[],
    map_to_parent={
        END: "selector",
    }
)

MENU_QUERY_HANDLER = ConversationHandler(
    entry_points=[CommandHandler("menu", menu)],
    states={
        "selector": [CallbackQueryHandler(selector)],
        "edit_subjects": [EDIT_SUBJECTS_HANDLER],
        "edit_grades": [EDIT_GRADES_HANDLER],
    },
    fallbacks=[

    ],
    )

The thing is, when I try to select any of the options, I have to click it twice to have a response. To manage the various selections I use the selector function, which is this:

async def selector(update: Update, context: ContextTypes) -> str:
    query = update.callback_query

    await query.answer()

    return query.data

Could it maybe be caused by this? Is there a better way to make a menu with InlineQueryKeyboard?