So sorry for the delay. This forum is new and it slipped my attention. I'm moderating for now.
You are correct; that seems to be a glitch in the Braille2000 programming. Dots 25 represent the contraction "cc" ONLY when it is between two letters so there is no need for the grade 1 symbol indicator in the instance of "https://" because the forward slash isn't a letter. The same for "c:\". If, however, you have "c:index" (I'm making something up; I've no idea if that would ever happen in the computer world.), then you would need the grade 1 symbol indicator because dots 25 are between two letters.