I have a T600 and the plugin was working great until I upgraded to unraid 6.12.X. Along with my CPU fan dying a slow death, macvlan errors that triggered a cache drive failure and restoring my appdata, and some other "joys," I was also seeing my T600 "disappear" and getting GPU errors in my logs similar to what others have posted.
Oddly, I tried turning off the netdata docker, and also uninstalled/reinstalled the GPU Stats plugin, and so far my T600 seems more stable. Previously it would fail and "disappear" from unraid until a reboot if I ran Plex or something that hit the GPU. It's only been 24 hours but wanted to share in case this helps users and/or the plugin dev.