What caused many temp files to be written to my home directory?

Today I noticed many files in my home directory mostly with long names of random letters and numbers. File says some are PEM certificate, some JSON data, JPEG, etc. They could be from web browsing but I didn’t open Firefox today. Firefox about:cache says “~/.cache/mozilla…”.

I did change my default group today. I rebooted.

Some files with the same names are in “~/.cache/mesa_shader_cache/”.

ps -u MY_USER:

    PID TTY          TIME CMD
   4474 ?        00:00:00 systemd
   4476 ?        00:00:00 (sd-pam)
   4490 ?        00:00:00 sshd
   4491 pts/6    00:00:00 bash
   5012 ?        00:00:00 dbus-broker-lau
   5013 ?        00:00:00 dbus-broker
   5044 ?        00:00:00 gvfsd
   5049 ?        00:00:00 gvfsd-fuse
   5056 ?        00:00:00 xdg-desktop-por
   5060 ?        00:00:00 xdg-document-po
   5063 ?        00:00:00 xdg-permission-
   5088 ?        00:00:00 pipewire
   5089 ?        00:00:00 wireplumber
   5107 ?        00:00:00 gnome-keyring-d
   5135 ?        00:00:00 at-spi-bus-laun
   6671 ?        00:00:00 gvfsd-trash
   6689 ?        00:00:00 gvfs-udisks2-vo
   6694 ?        00:00:00 gvfs-gphoto2-vo
   6698 ?        00:00:00 gvfs-goa-volume
   6701 ?        00:00:00 goa-daemon
   6710 ?        00:00:00 goa-identity-se
   6712 ?        00:00:00 gvfs-mtp-volume
   6725 ?        00:00:00 dconf-service
  12882 pts/6    00:00:00 ps

Switched to multi-user. Any user login now shows:

    PID TTY          TIME CMD
  15307 ?        00:00:00 systemd
  15310 ?        00:00:00 (sd-pam)
  15324 ?        00:00:00 sshd
  15325 pts/6    00:00:00 bash
  15359 pts/6    00:00:00 ps

So what does the command:ls -l ~/ show for the group owner of the files in your home directory.

What were you intending to achieve by changing your default group?

The new default group is the group owner of the files in my home directory. I needed to make my user match our standard installation.

This isn’t a question for RL then. Who ever set your org standard needs to explain how it is supposed to work.
It is more likely that they want you to become a member of a system group not change your user default group.
Since you are not providing any details we can only speculate.

I am the only administrator for this PC. This is for me to test our kiosk application. When a customer PC is built, my co-worker in Georgia runs our installation script as root and certain users are added and added to a group which gives us the same menus as the engineer group. Maybe we should have just added ourselves to the engineer group but this has worked for a long time. But the PC with the problem was installed by me and I was already on the system when the script was run so I was not in the correct group.

I logged in as a different user, renamed my home directory (for later reference if necessary), and ran the “users” script again. Now I am in the correct group and I have not seen the problem again.

Is it normal now that for a user that has just logged in, ps shows systemd and (ssh-pam) in addition to the sshd and bash I see on older systems?