Hello,
It looks like there is a decoding issue with sh404SEF.
We can see to patch the plugin to improve the final URL and make sh404SEF happier.
In the "stripeconnect.php" file (in the plugins/hikashoppayment/stripeconnect folder), please replace the line
$this->notifyurl = HIKASHOP_LIVE.'index.php?option=com_hikashop&ctrl=checkout&task=notify¬if_payment='.$this->name.'&tmpl=component&order_id='.$order->order_id.'&lang='.$this->locale;
By
$this->notifyurl = HIKASHOP_LIVE.'index.php?option=com_hikashop&ctrl=checkout&task=notify¬if_payment='.$this->name.'&tmpl=component&order_id='.$order->order_id.'&lang='.$this->locale.$this->url_itemid;
So it will continue to pass the Joomla menu ID to the different parts of the notification system so the final "after_end" generated URL will be SEF with a menu ID.
Regards,