Components automatically inactivate on error

I am running in an unusual behavior when running some of my “old” Knime workflows that have always worked in a different way in v4.x - when I run a component that has an error in it in the current Knime AP version (v5.2.5), such component inactivates rather than showing any error + red node color.

That’s how it looks from the main workflow:

And that’s how the “processing” component looks inside:

I can get some hint on the underlying error only in the log file:

Contains one node with execution failure (Case Converter #1872)

But it would be extremely difficult to test a more complex error, and right now the only option to debug is to extract the whole component content into the outer workflow.

Is this a known bug?

Thanks for your help.