Hi,
1: Have you checked your DHCP config on the device?
https://kb.juniper.net/InfoCenter/index?page=content&id=KB4243&actp=METADATA
2: If configuration is good then please check 'get event' if there is any error etc.
3: You can also try debuggin the DHCP with the flow basic, snoop and the dhcp debug
take the flow basic and the snoop along with the 'debug dhcp server"
4: BTW, where is it failing in the DORA process?
Thanks,
Vikas