ccr 1036 dns issue

i have a problem were the ccr is connected and dns is local server . works fine but some tp-link routers that connect to our ccr does nto get dns form the dhcp scope .

if you set it manuely in the tp-link it works but if not and set to automatically it does not pick up the dns setting set in the ccr .
if you connect straight to the switch connected with a laptop it works fine and gets dns like it supposed to .

any help

AFAIR, we faced the same problem with some tp-link routers not getting DNS via DHCP, and it was fixed by either upgrading or replacing them with other models.