IViews and List Views Not Loading on Web

We have created a new schema and set up a sample report as requested. Could you please check it now?

I’ve spoken with our .NET developer and a technical expert to analyze the issue. They confirmed that the GET call isn’t occurring for both iView and listView. In a fresh instance of version 11.3, we can load listView, but in the older instance, neither iView nor listView loads due to the missing API call. Could you check with your API team to ensure the calls are functioning correctly? We have also escalated this to the product team and will share any suggestions they provide. If you have another system available, please configure it for testing. Make sure not to use the current code; instead, install a fresh version and apply patches up to patch 14. Additionally, please remember to take a backup.