If I knew all the tools for diagnostics and troubleshooting I would not need this forum. I was simply throwing out an idea based on the fact that it seems to occur after I move large files, my RAM maxes out because of disk cache, and remains maxed out even 30 minutes after the file transfers are done. I suppose I can keep random observations to myself and post only output of commands that you specify.
Analyzing wild hypotheses has no merit. Rely on the system’s tools for analysis, such as ‘systemd-cgls -u user-1000.slice’ for user processes and ‘systemd-cgls -u system.slice’.
I assume you mean I need to run both tools every time before shutdown? It may be a week or more before this error is duplicated.