Empty page in "Previous posts"

Hello everyone, i am trying to solve a little problem here that i only discovered recently. Here’s what’s wrong:
go to https://www.frozendubs.com
press “drum and bass” category at top
scroll all way down
press “?? Previous“
boom! it’s empty – that is my problem.

The “?? Previous” button works perfectly at homepage, but not at categories.

Any thoughts?
Big thanks in advance!