I just joined this forum for this same issue. I previously used the SimBrief import option in the FMS, and it worked fine, but it only seemed to work before engine start. Recently, it has stopped working. I've tried different states, and tried inputting the Flight Number, but no luck. The most recent update didn't fix it for me either.
Still a fun plane and I use pretty simple flight plans so not a big deal but hope it gets fixed.