Looks like this is being tracked in PR1157692 and is showing as resolved in R4 so should work in R5. Since it does not they will need to reopen the PR.
https://prsearch.juniper.net/InfoCenter/index?page=prcontent&id=PR1157692
I submited a comment on the PR site so it gets some visibility but if you want to track the status directly you could open a ticket with JTAC.