I've been using the indi OnStep plugin for a while and had no problem with it, it only crashes when PHD2 is finishing calibration. I tried both on Intel and on Astroberry and the behaviour is the same.
Is there a way to see/log all the communication between PHD2 and Indi driver to see which specific command causes it? I guess I can try to run tcpdump on localhost and analyze that, but perhaps there is an easier way.
On intel I did run the latest version of the plugin from Jasem's repo, on Astroberry it was what it came with, I tried upgrading but it caused the driver to stop working so I probably upgraded it incorrectly.