If you have experienced any issue with Vipps try to enable Request Profiling or Debug features under vipps payment configuration area:
Stores -> Configuration -> Sales -> Payment Methods -> Vipps
Requests Profiling is a page in Magento admin panel that helps you to track a communication between Vipps and Magento.
You can find the page under System -> Vipps
On the page you can see the list of all requests for all orders that Magento sends to Vipps.
By clicking on a link Show in an Action column of grid you can find appropriate response from Vipps.
Using built-in Magento grid filter you could easily find all requests per order that you are interested in.
Logs which are related to vipps payment module are located under two files {project_root}/var/log/vipps_exception.log or {project_root}/var/log/vipps_debug.log.