Duplicated orders

-- HikaShop version -- : 5.1.6
-- Joomla version -- : 4
-- PHP version -- : 8.2

There is something seriously wrong with the orders.
There are duplicate orders and some do not even have an order number.
Credit card payments are not processed in these cases. There are no errors in the payment log for this period.
Only error I have
PHP Warning: Undefined array key "HTTP_USER_AGENT" in public_html/administrator/components/com_hikashop/classes/file.php on line 538

The database has not changed for years. Primary key is there.
Database check shows no errors and everything is ok.
The order number format has never been changed.

Order number format

{id size="5"}{date format="y"}

For four customers to do the same thing one after the other is a bit unusual or almost impossible.
In the case of credit cards, this would be theoretically possible. In the case of COD (on delivery), however, it is not, since the customer cannot return to the checkout after the purchase is complete.
Only I have access to the database and in this case I would know about the deletion. Massaction is not set up to do this either.

Enable multicarts was always turned off.
Login is not possible, only guest checkout is used.
Session lifetime is 100 min.
For order without a number, the history is empty.

Sent to contact.
After checking, I noticed that some tables in the database were blocked. Some process during the purchase causes the tables to be locked, thus preventing all further purchases.
I also noticed that the "stripe payment plugin" takes a lot of time (minutes) to change the status from created to confirmed. Could this be the cause?
GPT says:
HikaShop should create an order with the initial status created → and only after a successful Stripe webhook (e.g. payment_intent.succeeded) should it update to confirmed.

You are already doing this, but it is important:

that there are no active transactions or long-running UPDATEs left in onPaymentNotification() (or similar Stripe plugin method),

that after receiving the webhook, it only quickly updates the order status and does a commit().

If onPaymentNotification() calls slow operations (sending emails, API calls, logging…), execute them after commit().

max_connections - 300
performance_schema - OFF
All tables was allready InnoDB.

Again table locks and trouble with status change . Hosting support sent me this log.
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 24 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 24 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 24 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 24 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 24 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11592 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000
1020684 localhost Execute 25 Updating UPDATE `sjifs_hikashop_order` SET `order_status`='ready',`order_modified`='1754048832' WHERE `order_ 0.000
1000379 localhost Execute 11593 Sending data UPDATE sjifs_acym_user AS user JOIN sjifs_hikashop_user AS hika_user1_0 ON user.email = hika_user1_ 0.000

On that day I have also some php warnings, but I gues not related:
PHP Warning: Attempt to read property "shipping" on null in /public_html/administrator/components/com_awocoupon/helper/estore/hikashop/class-awocoupon-helper-estore-hikashop-discount.php on line 780
PHP Warning: Undefined array key 0 in /public_html/administrator/components/com_acym/Controllers/Segments/Edition.php on line 222
PHP Warning: foreach() argument must be of type array|object, bool given in public_html/administrator/components/com_hikashop/views/order/tmpl/listing.php on line 325

Any idea?

Order status ready is used for orders that are waiting for the customer to pick up. These are orders that are paid for via credit card or upon pickup. The status is changed manually by the admin.

I sent a request to their support for acymailing.

The status ready is used maybe a few times a week. The database hangs maybe once a month.
I think the problem with the status is more a result of some other error.
We use Acy on a daily basis. Up to 30,000 emails are sent per day via automation. Most of them are related to customers in one way or another.
Turning off the connection to Acy would represent a huge drop in sales.