Thanks Wims.

It makes full sense what you explain, but I am not getting it that way in the fp unless I start deleting multiple double or triple waypoints.

My "working" arrival misses BUN, D066K, CE25R and OM25R.

Just tried to make a fp for the flight  Schiphol to Monastir ( rw 7 ).
Again the arrival is messed up.
Net as much as with Brussels , but it is.

So you think that the issue might be cuased by Navigraph data ?
I always use the latest data.
If that is so I will contact them.

Also I will try with the PxxxMD-11 FMS, to see what the arrival outcome is.