Magento 1:在自定义模块中清空购物车信息

I have a custom module of Magento 1 that need to get the cart information. It works on several Magento installation, but in the last one I can't get the cart information. The version of Magento is 1.14.2.1 Enterprise Edition. I have no direct access to Magento, because our customer is in charge of Magento. They told me there's no custom modulo for the cart.

I've tried different strategy to get the cart info, taken from other thread, but the result was always the same.

This is the method that I've tried:

Mage::getSingleton('checkout/session')->getQuote()->getData();

Mage::getModel('checkout/cart')->getQuote()->getData();

The result is always the same:

Array
    (
        [store_id] => 21
        [is_checkout_cart] => 1
        [remote_ip] => <ip address>
        [x_forwarded_for] => <ip address>
    )

In all the other installation, both methods give me this result:

Array
    (
        [entity_id] => 684
        [store_id] => 1
        [created_at] => 2019-04-17 11:44:57
        [updated_at] => 2019-04-17 11:44:57
        [converted_at] =>
        [is_active] => 1
        [is_virtual] => 0
        [is_multi_shipping] => 0
        [items_count] => 1
        [items_qty] => 1.0000
        [orig_order_id] => 0
        [store_to_base_rate] => 1.0000
        [store_to_quote_rate] => 1.0000
        [base_currency_code] => NZD
        [store_currency_code] => NZD
        [quote_currency_code] => NZD
        [grand_total] => 64.9500
        [base_grand_total] => 64.9500
        [checkout_method] =>
        [customer_id] =>
        [customer_tax_class_id] => 10
        [customer_group_id] => 0
        [customer_email] =>
        [customer_prefix] =>
        [customer_firstname] =>
        [customer_middlename] =>
        [customer_lastname] =>
        [customer_suffix] =>
        [customer_dob] =>
        [customer_note] =>
        [customer_note_notify] => 1
        [customer_is_guest] => 0
        [remote_ip] => 172.20.0.1
        [applied_rule_ids] =>
        [reserved_order_id] =>
        [password_hash] =>
        [coupon_code] =>
        [global_currency_code] => NZD
        [base_to_global_rate] => 1.0000
        [base_to_quote_rate] => 1.0000
        [customer_taxvat] =>
        [customer_gender] =>
        [subtotal] => 60.0000
        [base_subtotal] => 60.0000
        [subtotal_with_discount] => 60.0000
        [base_subtotal_with_discount] => 60.0000
        [is_changed] => 1
        [trigger_recollect] => 0
        [ext_shipping_info] =>
        ...

Last things. I don't know if this information could be useful, but it is the only difference that I saw with the working installation, but I don't know what it could mean. In the not-working installation I have these value in the Mage_Sales_Model_Quote object:

[_oldFieldsMap:protected] => Array
    (
        [base_customer_balance_amount_used] => base_customer_bal_amount_used
        [gw_add_printed_card] => gw_add_card
        [gw_printed_card_base_price] => gw_card_base_price
        [gw_printed_card_price] => gw_card_price
        [gw_printed_card_base_tax_amount] => gw_card_base_tax_amount
        [gw_printed_card_tax_amount] => gw_card_tax_amount
    )

[_syncFieldsMap:protected] => Array
    (
        [base_customer_balance_amount_used] => base_customer_bal_amount_used
        [gw_add_printed_card] => gw_add_card
        [gw_printed_card_base_price] => gw_card_base_price
        [gw_printed_card_price] => gw_card_price
        [gw_printed_card_base_tax_amount] => gw_card_base_tax_amount
        [gw_printed_card_tax_amount] => gw_card_tax_amount
        [base_customer_bal_amount_used] => base_customer_balance_amount_used
        [gw_add_card] => gw_add_printed_card
        [gw_card_base_price] => gw_printed_card_base_price
        [gw_card_price] => gw_printed_card_price
        [gw_card_base_tax_amount] => gw_printed_card_base_tax_amount
        [gw_card_tax_amount] => gw_printed_card_tax_amount
    )

Thanks