It depends at what level your question is. I mean that searches for dibaryons in general are still performed, because there are theoretical motivations. So telling you "those do not exist" is a bit partial...
At least for the diproton, you can easily imagine that this bound state is extremely similar to the deuterium which (for electrical repulsion) is more stable than the diproton. So a diproton would decay very very very rapidely to a deuterium.