localhost and jquery ajax requests are not responding on the new tab or in new window after php form submission

Hi i am submitting a form using php. php form submission takes 5 to 10 min depending on the file sizes because i am uploading csv files and processing the files data after uploading the files on my localhost.till here all works fine, mean while if i open any new localhost project on a new window or in a new tab then the localhost dont responds to me until all the files are uploaded and all files are processed in my other tab on which the form is being submitted. also if i send any jquery ajax request on any other tab or window while form is being submitted then it shows this in the chrome network tab. provisional headers are shown

means the server is not returning any response.

but after the form is submission is completed and files data is processed then the jquery ajax request are also returning me the status 200k and the response

Kindly help me on this please.

Thanks and Regards

M.Usama