Console throws "Forbidden" _layouts/15/WsaUpload.ashx on attaching a file

Question

I am experiencing Forbidden error in console on URL "https://site/_layouts/15/WsaUpload.ashx" (see the image below) when attach files via OOB Form in the Modern List (SharePoint 2019). I have also noticed that the changes are not getting reflected asynchronously after uploading the file. Should to refresh the page to see the attachment(inside the OOB Form). Anybody has got this error & resolved?