S138: TransAction Token lifetime very short?

[Thomas.Zygadlewicz]

Hello,
 
I'm using the Transaction Token in my Struts138 App. But it seems the
token has a very short lifetime. I guess about 1-2 Minutes. How can I
manually correct it?
My inactivity timeout is set to 20 mins - so my token should be set to
the same value.
Can someone tell me how and where?
 
Regards, Tom