Black Symbol next to Column Rename Processor

Hello there,
one quick question:
what does this black symbol next to the processor mean? Is it a warning?

Thank you!

Hard to they. Seems like the original symbol is broken and not displayed correctly.
Is it reproducible?

I have it on my instance in several workflows but I couldn’t reproduce it on other instances yet.

does the problem disappear if you hard-reload the page with CTRL + SHIFT + R?

Yes it is still there.