My hypothesis/interpretation: I believe there is black hole's credit here. There may be more than one path for FRB to travel the Earth. For example, through a straight line (geode in geometry), but not thru a black hole to reach the earth directly. And for example, through a black hole. It's possible to also pass through several black holes or a black hole several times. Thus they are the same FRB, but due to the complex geometric topology of the universe, the delay of arrival time in different paths are generated.
