Ah, sorry to hear that! This isn't something we've previously heard of, so it might be difficult to reproduce and solve.
Could you let me know if this is the same with all enemies after you first encountered it, or just Barkplug?
And is it just Nugget (if you're not sure, you could try a healing item of buffing ability to get to Sausage — it would also be useful to know if this works as well).
Also, does the marker appear on Barkplug like it does with the previous enemies, or do you not see that either?
We finished work on this quite some time ago, but we can try to reproduce on our end.