(ACC V8) jssp : logonEscalation('admin') - Session has expired or is invalid. Please reconnect.

Hello,

we developed a jssp with the use of an xmlHttpRequest (post method) to transmit the data triggered following the click of a button. We then use a server-side js function to retrieve this data and call a postEvent to trigger a workflow.

In V7, we used this code to do the postEvent : 

oldContext = logonEscalation('admin');

xtk.workflow.PostEvent('wkfInternalName', 'signal', 'done', parameters, false);

In V8, this code no longer works (probably due to the IMS connection mode) and we have this log : 

XSV-350008 Session has expired or is invalid. Please reconnect. (iRc=-69)

If someone has an idea ?