Adding nested triple to blank nodes in OntoRefine not possible?

I'm using the latest version of OntoRefine and want to add a nested triple to a blank node. I'm following the exact instructions on Ontotext website. In the interface there is supposed to appear an arrow next to the object (in the picture on the right side, just under the waste bucket). But it does not appear when the object is a blank node.

It does appear when I create an IRI, but in my case a blank node would be the way to go. When I import the files that are in the tutorial on the Ontotext website, I still do not see the nested triples that are in the example. However...... when you export as RDF, the correct triples - including the ones with the blank nodes as subject - are created.

So it seems that the functionality works, but the interface does not support it. I was also able to manually change the JSON file for my own data and got the correct RDF triples.

Question is: am I the only one that has a problem with the interface? Am I doing something wrong or is this a bug? Curious to know what your experiences are.

in what version of GraphDB are you facing this issue, as problems with blank nodes in the OntoRefine's RDF Mapper have been addressed in GraphDB version 9.5.