After executing successfully the shell script the workers remain stuck for 10 minutes on the final "exit 0".

There hasn't been any other failure that I could find: all the jobs run exactly as planned, they just don't seem to exit.

The fact that the jobs remain stuck for exactly 600 seconds makes me think of a timeout of some sort.

Reverting to 2.138 fixed the issue, that's why I am marking it as a regression.