Zend certified PHP/Magento developer

No such entity with orderId=

last few days i have been struggling with a weird issue with my magento 2.3.4 site(its a new installation and is hosted on a webserver). When ever i try to do an transaction by making payment (in test mode) through credit card using a payment gateway- my order fails and i get this error of no such entity with order id=
I noticed this issue only recently after i integrated with paypal express checkout. I had done several successful tests earlier with the same payment gateway without any issues.
I checked the logs at the payment gateway end and all my transactions are successfully getting captured with an order id(!) but the same is not getting reflected on the frontend (pls see the 2nd screenshot)

I tried completing the purchase transaction using COD and my order gets generated without issues.
I did a debug traceback after going through the previous posts and got the following results (though i have not been to make heads or tails of the same, pls refer the traceback screenshot

I also checked the debug report in the var/logs/debug.log and noticed several broken references. While i fixed some (like re-installing yotpo after i noticed yotpo-bottomline trying to reorder itself towards product.info.addto, removing some extensions like ves_imageslider etc).
However, there are large number of broken references which i don’t how to fix as they are magento(??) issues(or is it my porto theme);


[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘tracking’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘global_notices’ element cannot be added as child to ‘global.notices’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘logo’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘global.search’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘user’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘menu’ element cannot be added as child to ‘page.menu’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘breadcrumbs’ element cannot be added as child to ‘page.breadcrumbs’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘formkey’ element cannot be added as child to ‘page.formkey’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘page.title’ element cannot be added as child to ‘main.top’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘messages’ element cannot be added as child to ‘page.messages’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘page.actions.toolbar’ element cannot be added as child to ‘page.main.actions’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘legal’ element cannot be added as child to ‘footer’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘notification_area’ element cannot be added as child to ‘notifications’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘unread_system_messages’ element cannot be added as child to ‘notifications’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘notification_window’ element cannot be added as child to ‘notifications’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘notification.messages’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘header.inner.left’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘header.inner.right’ element cannot be added as child to ‘header’, because the latter doesn’t exist [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘logo’ tries to reorder itself towards ”, but their parents are different: ‘header’ and ” respectively. [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘global.search’ tries to reorder itself towards ‘logo’, but their parents are different: ‘header’ and ” respectively. [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘user’ tries to reorder itself towards ”, but their parents are different: ‘header’ and ” respectively. [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘page.actions.toolbar’ tries to reorder itself towards ”, but their parents are different: ‘page.main.actions’ and ” respectively. [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘notification.messages’ tries to reorder itself towards ‘user’, but their parents are different: ‘header’ and ” respectively. [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘header.inner.left’ tries to reorder itself towards ”, but their parents are different: ‘header’ and ” respectively. [] []
[2020-04-02 16:11:50] main.INFO: Broken reference: the ‘header.inner.right’ tries to reorder itself towards ‘header.inner.left’, but their parents are different: ‘header’ and ” respectively. [] []

Any insights to fix it would be much appreciated.

thanks & regards,
Harish

[The Error
[The payment gateway results
[debug traceback sceenshot