@coconnor 

It seems to be a glitch for some users.  I personally have not had the issue but there are a couple of other posts from the past couple weeks that others are having the exact same issue.  Unfortunately, QB is not very good at keeping their customers informed on these issues.  I'm sure you're aware that you can reverse a JE manually.  Other than the reversing JE # being the original JE # with an "R" at the end and a memo that reads "Reverse of JE #", entering it manually does the same thing but is a bit tedious.  Hopefully, they resolve it soon.