I have seen a number of recent merges where the parents are being lost during the mege.
The problem seems to happen when the high number profile has the parents, but the low number does not does not. The person doing the merge does not realize that it is necessary to actually mark the parents so that they will be carried forward to the merged profile.
If the parents are in the low number profile - everything seems to be OK.
I suggest that the system be changed so that if parents are in either profile before the merge that they be used in the merged profile.
This current pending merge is an example - Merging Clemens-1527 into Clemens-543