Amazon 5 monthly instalment payment option - where did it go?

I've used Amazon's 'pay in 5 monthly instalments' payment option many times in the past, never missing a payment. Previous items I've used it for include PC motherboards, processors, speakers, headphones and an office chair. Nowadays it seems to only be available for Amazon-owned brands - so the Echo, Fire, Kindle and Blink range...and not much else. Anyone know why? Amazon customer services couldn't really say why.

Welcome your thoughts.

Cheers