Comment # 3 on bug 1037592 from Christopher King-Parra

(In reply to Dominique Leuenberger from comment #2)
> How did you get to the conclusion that the cron job is running? Any log
> files to support that theory?
> 
> I rather suspect that you have a GNOME desktop in front of you and GNOME
> Software is installed, which handles the lookup of updates out of the
> desktop session - not via the PK cron job.
> 
> The command "gsettings get org.gnome.software download-updates" will show if
> this feature is enabled
> 
> using "gsettings set org.gnome.software download-updates false" it can be
> disabled; but note that GNOME will not inform about any pending updates in
> this case.

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> How did you get to the conclusion that the cron job is running? Any log files to support that theory?

I assumed, wrongly, that there was a syntax error after reading the cronjob. 

Running `gsettings get org.gnome.software download-updates` did indeed show
that it was set to `true`. (It must have been set after installing flatpak.
..another assumption.) 

After setting it to `false`, and rebooting a few times (to test), the
notifications seem to have stopped. Sorry to have taken up your time with this.
I meant well.