Hi,
we weren’t able to reproduce this issue in our labs so far. Can you please send us the “.xsession-error” file located in the home directory of the user owning the desktop?
Also a full set of logs could be useful. You can gather them following the guidelines in this article: https://www.nomachine.com/AR07K00677.
You can send files to forum[at]nomachine[dot]com.
Can you please also explain what you mean exactly with “remote pc freeze, but only Gnome Shell”. Other applications continue to work?