Why does IE reset session on ajax request?

Question

JavaScript

When sending $.post() requests, IE does not always send a cookie containing the session ID, while the rest of the data is sent successfully. Thus, the session is reset and there are problems with the functionality of the resource. The session cookie is assigned as usual - until the end of the session and works quite adequately for some time.

All functionality of the site works on all browsers without problems, with the exception of IE, problems have been identified on home IE11, on IE10 in a remote terminal and on IE8 in a virtual machine.

In the code (php, js), the session is not deleted in any way, because it does not work only in IE, and the search for the project did not give anything.

Maybe someone met with such a problem and knows something that I do not know? Or at least where to dig?

Answer 1

Most likely, cookies exceed the limit.
4096 bytes per file, 20 files per domain, something like this