Is there any way to establish session with client (webapp with browser enabled authn, not a Bearer type) by XMLHttpRequest?

I have central webapp which provide access to other services (restful). The problem is that when I login into central app I establish session with jsessionid connected to it. That works fine until I try to access other services. I have front-end as a single page (ExtJS) which issue XMLHttpRequest to service (separate web app in the same server). By the time I login into central app browser has its jsessionid, but to access other service, I need to establish another session and keycloak has to generate another jsessionid for me to access this service. And I can't get it supposedly because of XMLHttpRequest not a HttpRequest.

For example, for this request (with jsessionid of central webapp):
GET /rest/test HTTP/1.1
Host: localhost:8080
X-Requested-With: XMLHttpRequest
Cookie: JSESSIONID=XAVXi...
Connection: keep-alive

Response is (I ommited some unimportant headers):
HTTP/1.1 401 Unauthorized
Expires: 0
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
X-Powered-By: Undertow/1
Server: WildFly/9
Pragma: no-cache
Connection: keep-alive
WWW-Authenticate: Bearer realm="Unknown"

And when I change request to generic http, I got correct jsessionid and can access my rest service.