Can the following TR apply to your case?
If not, please provide the following info.
With frozen you mean that you see the remote screen when connecting but it won’t update? Or that it will update, for example when the clock changes, but input events are not working?
What are your Linux and desktop environment versions?
Logs can be useful. You can gather them as explained in https://www.nomachine.com/AR07K00677 and send to forum[at]nomachine[dot]com.