Client machines and Sub CA still points to old root ca

hello ,

i have uninstalled the whole PKI setup and re installed a fresh rootca server and reinstalled the certificate role on my subca server

all services on the sub ca has been started successfully and no errors , however all machines still pointing to the old root ca when requesting the certificate how can i change this

i checked the default group policy and mak sure that only the new rootca is there but still no clue !