portamento tonguing on final note issue

Hello,
I'm currently working with portamento glissandos for trombone. I installed a soundfont that allows portamento glissandos, but I noticed that the final note was played twice. What I mean by that is that instead of sliding from one note to another and holding that note, it would slide from one note to the other and then play that final note again. I checked it out with electronic instruments, which have portamento glissandos native to MuseScore, and it still played the final note again, meaning it is an issue with MuseScore, not with the soundfont. Has anyone else had this problem and gotten around it? I wouldn't mind a work around as long is it's not too complicated, although a fix or an option would be better.
Thanks,
Alijah