connection - Android Lollipop defaults to Mobile Data when Wi-Fi has not Internet access? -

android lollipop seems default mobile data when wi-fi connected has no internet access. know if officially documented somewhere?

we have application needs connect machines via wi-fi not have internet. our customers reporting wi-fi connection not work anymore, because phone automatically switches lte.

my understanding phone still keeps wi-fi connection uses lte in addition provide access internet (lollipop-feature-spotlight-android-now-defaults-to-mobile-data-when-wi-fi-has-no-internet-access-signal-icon-adds-a-for-no-connection).

is understanding of feature wrong? , if so, there way force using wi-fi without internet? not find in particular in developer documentation.

any appreciated.

to extend on @ianhanniballake's answer, i've found binding network using connectivitymanager.setprocessdefaultnetwork() prevents roaming , allows full tcp access. thus, within onavailable() callback bind application process network rather opening connection particular url.

connectivitymanager connection_manager =      (connectivitymanager) activity.getapplication().getsystemservice(context.connectivity_service);  networkrequest.builder request = new networkrequest.builder(); request.addtransporttype(networkcapabilities.transport_wifi);  connection_manager.registernetworkcallback(request.build(), new networkcallback() {      @override     public void onavailable(network network) {         connectivitymanager.setprocessdefaultnetwork(network);     } }