Thank you, it seems to work normally if I change the calling part to ${data} (the function still gets a dictionary, not a string). Somehow in my testing I either didn’t test this variant, or something else went wrong when I did. Anyway, since it seems to work now, I can continue my work and will create a issue for you.
Btw. the &{data} variant worked in the old version of the code without embedded variables, and since I’m new to robot, I assumed it worked a bit like Perl and you had to use & if you wanted the variable to stay in dictionary form.