Beastiary Scarab of Duplicating Not Duplicating

I've been running this scarab for almost a week now and today I noticed that none of my captures are being duplicated anymore.
Last night, I capture a Craicic Chimeral and it duplicated fine, found another one and a Black Morrigan and neither duped. Anyone else experiencing this?
I do also want to note that I keep my beast book full and just let the good ones replaces that bad ones, could this be something to be weary of?

not sure what I changed, but working now.

NVM, happened again with black Morrigan.
Is the duplicating not working or failing some times because of the replacing beast book?