@jmb73, I haven't experienced nails separating but I have heard about it. It could be onycholysis. Mayo Clinic has some information here - Fingernails: Possible problems - Slide show: 7 fingernail problems not to ignore: https://www.mayoclinic.org/healthy-lifestyle/adult-health/multimedia/nails/sls-20076131?s=6

Here is more information with details -- Onycholysis (Nail Separation): Symptoms, Causes & Treatment: https://my.clevelandclinic.org/health/diseases/22903-onycholysis#management-and-treatment

I have no medical training or background but I'm not sure I would take the it's from aging answer without asking more questions - Have you thought about getting a second opinion?