[Execution Engine] Apply tags to children sometimes does not deliver finished message

[markus-moser]

It feels a bit random, but sometimes we get a finished event via mercure and sometimes it stops at some point without additional finished event / final status update (and also no visible error when running messenger:consume).

[markus-moser]

I'm not sure but it seems to be the case that this happens when I have multiple parallel workers (from different containers) running.