DHCP on S4112T-ON

We are working on implementing new Dell switches into our network. We will have dual S4112T-ON switches as the cores, and access switches (N3248TE-ON) for each wing or "area". We currently use Unifi APs and switch to provide wireless using RADIUS server, and DHCP is assigned via DHCP server on a Windows server. In the new system, we want to move to providing DHCP from the access switches and discontinue use of a DHCP server on Windows server. We will be isolating wireless to its own VLAN and would prefer to have the core switch provide DHCP for that VLAN since it covers all areas. We've set up the DHCP pools on the cores and have the trunk between the access switch and cores configured to allow the wireless VLAN to cross. To test the DHCP, we connected an AP to an access port on the access switch configured for the wireless VLAN, but cannot get it to get a DHCP assigned address still. I've tried ip helper addresses, but they don't really work. Any suggestions?