Although the RFC for cookies implies that dashes are OK in a cookie name, others have experienced issues with using dashes in a cookie name.
Try changing the name of the cookie to something without a dash. Only alphanumeric characters are allowed, but underline characters seem to be OK.
Reference this question/answer: https://stackoverflow.com/questions/18907771/can-http-cookie-name-contain-dashes/27235182 ; the accepted answer includes references to the RFC.
I personally try not to use dash characters in anything, unless I want to ‘subtract’.