I looked further, and found a crash file on the “server” side for nxnode. I followed the instructions on https://www.nomachine.com/AR09L00810 to generate a backtrace after extracting the core dump from the apport utility.
The core dump is >300Mb, though I knocked that down to 4.3Mb with libxz. I’ll attach the backtrace log for now. If you also want the core dump, please instruct if you have a preferred method to attach large files.