Dependant Insurance Q

My ex has carried our son on his insurance for years and suddenly my son was dropped from the insurance plan. The ex states that this is because CVS now has more stringent requirements for dependent insurance. Apparently, now he must provide corporate HR with proof of dependency by one of the following means:

- proof of (child) support being paid
- proof of residency by being enrolled in the school district
- claimed on taxes

Needless to say none of the above could be provided as it either hasn't been done or it wouldnt be true.

My request for assistance isnt to complain about anything that isnt happening (child support). I am just trying to figure out if what I am being told is correct and any assistance to that nature is requested.

My son and I thank you for your help!