My pair of very mature (~40 years) deep pink varieties have yet to bloom.

Yeah I ve got 10 crepe myrtles total in my yard.Ive got 4 white ones.The 2 white ones in front are beautiful, Been blooming right at 2 weeks now. My other 2 whites on the side of the yard arent blooming yet.That makes no sense as all 4 are of the same breed and the same height.Also I have 2 light purple ones.1 has been blooming the same time as the 2 white ones in the front and the other just yesterday finally started blooming..I know the reds and pinks always bloom a little later on, especially the dark red ones.I have a 1 dark red, 1 purple, 2 pinks and the 2 white ones that havent bloomed yet.