Edit: well the reset worked. Hard to believe, since I had done a proper reboot earlier!
I forgot to mention, I did reboot before posting. I just tried to access the nvidia plugin and the gui became unresponsive. I don't know what would be using all the memory, dashboard with Docker off sits at 38% ram used.
Because the gui was unresponsive and I couldn't get a shell, I did a reset. It triggered a parity check of course. The system came back on good, I can access the shell now. Checked the log since reboot, all good, no memory errors or nvidia errors. I'll wait until the parity check is over and then I'll open a shell just in case and try to turn Docker on. Hopefully everything is good now.