Not sure of my responsibility vs. the guardians

I'm a caregiver for my 21 yr old adult autistic son.. he has been deemed incapacitated n a guardianship was done.. within the guardianship court it was deemed my ex husband and I had to much conflict to name me guardian so the county in Missouri where my son lived when he turned 18 was granted guardianship and I the caretaker... that was almost 2 years ago though he's been in my care full time for more.. we have been residents of the state of Kansas since papers were filed in probate court n Aaron is also a legal resident of the state of Kansas since before guardianship was finalized.. we live 2.5 hrs from the county in a different state that was assigned as his guardian... his guardian we have only met n spoke with once which was the day of the trial n that's it.. I have been dealing with a case manager from Jackson county Missouri since.. in the last yr to date we have seen her 1 time in person n that was January 2020.. and we have spoken to her 3 times on the phone... all other contact is email or through a 3rd party that also works for Jackson county guardians office... I'm having a difficult time trying to define what is their offices responsibility n what is mine as the caregiver... my ex husband kept my sons ss card when he moved in with us and with only his birth certificate as proof of citizenship n identify he can not get a replacement ss card.. I have tried everything n followed everything the case manager has told me n still a year later nothing.. my son can't cash his checks sent to him by the same office without an ID so he has no access to any of his funds and literally can't do or sign up for anything without an ID... this has been going on for well over a year.. the case manager says it's my responsibility to get it taken care of n continues to blame me for the delay but I have no legal rights to request anything or sign anything as the caregiver... where does the responsibility of the guardian start n the caregivers end?