Thanks so much for the theme information - very helpful and a nice looking theme.
It's possible that themes like this (that have lists of 'related' or 'featured' posts) can lose track of the 'current' post while they are looping through the other lists, which means things lower down the page might not be able to access the 'current' post. I've checked the Hueman theme and it all seems to be good, and I've not been able to reproduce the problem - although as you point out, some sites work just fine.
I've tried a workaround and released an updated version 1.4.4 of the plugin. It tries to capture the information the breadcrumbs needs as soon as possible; that should mean the data will be the same wherever it's used - header or footer. Give this a try and let me know if it helps! If not, I'll have to look a bit deeper.