this is also a sim limitation, or a bug (can´t 100% verify) and one of two reports which are still open at ASOBO (one is the approach-transition issue and one the “removing” waypoint issue, when you add an approach).
Look at here, there was a similar report at Dublin (EIDW) and there are a lot of such situation worldwide:
You can test it by your own in the worldmap:
select the VELO1L STAR only (approach still on automatic)
You see, the STAR is cutted at NEDIV and the approach starts at BAMPU … why? We don´t know but that´s a general issue in the sim-engine also and has nothing todo with the using navdata. It happens with the default NavBlue data also.