The albino mutant first appeared in the 80’s set X-Men: Apocalypse (played by Tómas Lemarquis), using his mutant tracking ability to help both Mystique and Apocalypse.
Then he appears as a supporting character in Logan played by Stephen Merchant, and he’s basically an entirely different character, complete with a different accent.
If you thought that the X-Men movies were finally going to get their shit together after Days of Future Past, then let me present Case A: Caliban.
The folks over at Nerdist asked Logan director James Mangold about this snafu, and he admits that’s it was a product of confusion and just generally no one keeping tabs on things.