Hello Albert,
I feel I belong to the last generation which still knows by memory where our ancestors graves are located.
In order to help the followers to occasionally visit our families graves, I started surveying graves with GPS.
I am experiencing difficulties to specify in which grave such ancestor was buried. I could not update the location of the burial. It is systematically reverted to the prior location.
Should I cancel the burial event and recreate it with the grave location?
Did any of you met and solve that problem?
I never used coordinates up till now, but I just tried adding them, and found that Gramps does seem to save them properly. That means, that when I open the same location later, I see the coordinates that I entered. I tried this with the Windows version and the latest 3.4 development version on Xubuntu.
There is a scenario that can easily go wrong however, and that one occurs when you have several family members buried in different graves on the same grave yard. Now, when you have one location entry in Gramps for that grave yard, every time you enter coordinates for a grave on that yard, you actually change the coordinates of the grave yard itself. So, when you enter coordinates for two graves on that same yard, in sequence, you will find that when you check the position of the first grave, you see the coordinates that you entered for the second one, which makes you think that it is somehow reverted. And the answer then is, that it was reverted, by yourself!
As far as I know, Gramps can only store coordinates in the location table, so you have to make sure that each grave gets its own entry in that table. That means that you are sort of forced to use location names that include a grave number, or grave name, so that you can keep those entries separate.
I hope that I guessed right, and that this solves your problem. If it does not, please tell us exactly what you did, so we can reproduce the problem.