Double atlas book of skill from eater of worlds quest (Solved)

I obtained two atlas books of skill from Kirac after completing the eater of worlds questline.

What I think might be of influence:
- I killed Eater on my friends map device before ever turning on the Eater compass
- I have used the flesh compass on the map device before that
- I did not have the Exarch compass at the time
- I rush completed the quest myself afterwards

As an additional note: I also got the voidstone after killing Eater with my friend, not sure if that's intended.
I have not used the books, as I am not sure if it causes problems.

You receive atlas books for completing both the Infinite Hunger and Eater of Worlds fights.

Similarly, you will receive books for both the Black Star and Searing Exarch fights.

That explains it then, I did not realise that was a thing.
Thanks!

I have the same issue