Now we know we cannot take the same feat multiple times.
What about when something else gives it to us?
Imagine you are a Human who took the general feat Adopted Ancestry (Halfling). Then on level 5, can you take an Ancestry feat (Cultural Adaptability) which happens to give you the general feat Adopted Ancestry?
As I quoted in the linked question, feats you can select multiple times tell you happens when you do so:
Special Usually this section appears in feats you can select more than once, explaining what happens when you do.
It seems clear enough to me that the intent is that you can only take a feat multiple times if the rules tell you what happens when you do so. This isn’t clearly spelled out, hence your question, so the GM has room to rule otherwise.
