Soft linked services not showing in IT Services tree because of dot in the id string

We are testing the upgrade from 1.8.10 to 2.0.8. I don't know if this is related.

The problem:
We have some soft linked services. You can see them with "display: none" in the source code, but clicking on the "+" of the parent services fails to show the soft linked child services (doesn't matter if in Monitoring or Configuration).
I did some debugging and could find out that the problem is the dot in the css id.

The original javascript call doesn't work (verified with the inspector console of firefox):

jQuery('#id_' + nodes[i]).hide();
=> jQuery('#id_2.239').show();

escaping the dot does the trick:

jQuery('#id_2\\.239').show();