Response to preflight request doesn’t pass access control check: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘<domain>’
It was very annoying. Ajax request not works perfectly in IE. But when developer tool is opened ajax quires are works fine. It was very cumbersome . It happened because IE chache Ajax requests. When Developer tool opened it is always refresh from server. I get this fixed by making cache false in ajax request. I think it might help you.
Some times it is best idea to issue multiple Ajax request in parallel. Without waiting one request to be completed we can issue multiple request using jquery when method