IMO disable all collisions of the bomb component but the sphere collision component and work from there. Assuming you conly need 1 component in that actor to collide.
You could set the bomb with no collision by default and enable it when thrown… or create a preset for holding and another for thrown.
Also might be a good idea to save a pointer of the instigator and on the overlap / hit check for it to avoid triggering on the wrong actor.
Hope it helps.