It's likely a combination of things. Poor marketing, competition from other shows, and changes in audience preferences might all have played a role in Beyond Belief: Fact or Fiction getting the axe.
I don't have the definite answer. You could try looking on manga forums or social media groups dedicated to it to see if there's any consensus on whether it was cancelled.
It's hard to say. Sometimes a fictional work can be cancelled due to low ratings or financial issues. But there could also be other reasons like creative differences or changes in the market.