I believe you have this issue because you are working from a network drive (prod.corp.hycite.com) which is not mapped to a drive letter.
Pandoc and R Markdown have issues with network drive. You can find several Q&A in here and in the github issue board.
I would advice to map the network drive to a drive letter (like Z://) and at least update all packages + pandoc
This way your paths wouldn't start by \\
Example possibly related this thread (Error when knitting RMarkdown to HTML on a networked drive - #13) or this issue (https://github.com/rstudio/rmarkdown/issues/1268)
Possible help on context in here: 49 R on network drives | The Epidemiologist R Handbook