Problem with LTI/Tsugi integration

Hello,

I have a XOT 3.6 set-up with Moodle authentication (Ubuntu 16.04, Apache/2.4.18, PHP 7.0.30). I am very interested in the new LTI/Tsugi functionality, so I followed the introduction of how to install Tsugi for Xerte, which seems to have succeeded. Now I have the following problem:

Every time I go to project properties -> LTI/xAPI and navigate away afterwards (even if I don't change any settings), I have been logged out of Moodle/Xerte. Similar situation if I navigate to a learning object published via Tsugi/LTI with Moodle external tool: I get an error that the service is not available, and I am looged out of Moodle/Xerte. Both apache and php logs do not show any interesting entries.

Regards,
Thomas