MeshMergeParam issue at restart

Hello!
I tried to apply the technique shown here:

and works really great. There is only one issue: every time I restart the editor, the skeleton parameter disappears from the structure, as shown in the picture:

Every time I need to recompile, remove the setter and place it again to make it work. Any clue?

Thanks!

I still did not find a way to make this work with blueprint only. The workaround I found was to just create a function that does all that in C++.