Process is in sleep state but WCHAN shows - in Red Hat Enterpris Linux 8

Issue

• Some user processes' WCHANs show - though the processes are in sleep (S) state.

  # ps alx
  F   UID   PID  PPID PRI  NI    VSZ   RSS WCHAN  STAT TTY        TIME COMMAND
  [...]
  4     0   807     1  20   0 399784 28448 -      Ssl  ?          0:13 /usr/libexec/platform-python -Es /usr/sbin/tuned -l -P
  [...]
  4     0  1644     1  20   0  93048  9492 do_epo Ss   ?          0:00 /usr/lib/systemd/systemd --user
  [...]