It’s not as problematical as it used to be.
Don’t worry folks! Everything’s under control! As I understand it, they are leaning towards the “oscillating neutrinos” explanation. “It’s the physics, not the model.” I believe there are efforts underway to produce this effect experimentally.
It seems to be part of the general trend of “obscuram per obscurius” - ( explaining) “the obscure by means of the more obscure”. Cf. John Horgan’s book, The End of Science. He spoke to my condition.