Yep, I came across this bug with my bard too. If you long rest and come back, Rugan should be gone and you’ll be able to pick up the chest so there is a workaround, at least.
If the same thing happens to you as me, then you’ll also get a bug when you get into the Zhentarim hideout that Rugan mentions and miss a cutscene that I believe is meant to happen. I’m not sure if this bug happens with all classes or just the bard (I’ve seen it before on at least one other playthrough in an earlier patch, but can’t recall if that was also a bard). But I won’t say what the bug is here in case you don’t get it and I spoil the plot for you!
