The light emitted by sea pickles doesn't follow the gradual-strengthening law of all lights in water when a person dives in

As far as I'm concerned all lights in water are lights, right? I think the light emitted by sea pickles is supposed to be gradually strengthening too when a person dives into water, instead of reaching its maximum intensity the exact moment he/she touches water, which happens in 18w14b.
I don't know if other lights such as magma blocks or sea lanterns have the same issue.
Sorry if it's another issue which works as intended.