After performing a wireshark capture I figured out what the issue was en resolved the problem. VLAN tagging in bridge mode where the AP is in a different VLAN can get tricky as the broadcast from client to dhcp server is in layer-2 and the dhcp server offers in layer-2 and layer-3 (broadcast and unicast). See below article; Solved: DHCP DORA--> Broadcasts or Unicasts? - Cisco Community De solution was to change the mode from Bridge to layer-3. The delay problem is resolved now. ... View more