Butter Notes?

I roasted a Colombian Wush Wush last week and have been noticing an interesting note.

Its got the notes I was looking for (strawberry and cocoa), but it has a slight note of butter.

I used to be a professional brewer where butter was a massive quality red flag, but I can't find anywhere stating this is a flaw in coffee. In fact, I see people hunting for buttery flavors.

Did I roast this wrong or is this someone's holy grail bean (just not mine)