@vvanier This is how I finally got it to work with Mojave. So far it's
giving me new troubles on my Catalina test machine. Only a few of the
teachers seem to be using it now though that I might just ditch it for
next year.
I suddenly got it constantly (respawn about 1.5 seconds) on all my
student machines after 10.14. I spent all day on it. For me it was
Siri.app in restricted software. Sometimes it pops up once per user now,
but at least it's easily dismissible.