I already fixed it using the tilde on the keyboard instead of copying and pasting from the spreadsheet. Just thought it was interesting that there are 2 tilde characters.
From jsx, .charCodeAt() reports code 8764 from what was in my spreadsheet. That is apparently the "tilde operator" character, not the normal tilde.
I have no idea how I got the 8764 character into the spreadsheet in the first place instead of 126. So, just typing in the file name and all is good 
Apparently some scripts / text editors interpret some characters that way. Sometimes that may happen when you change font, size or something else that text is processed. I do not know which editors do that but saw others with same problem.
Or there's default encoding during saving sheets of such editor that translates characters to certain encoding if not specified.