DHCP trap issues for TT workflow

We have been noticing an issue with DHCP for HSI service in TT workflow. So here is what is happening. 
The "isDhcpRequired" flag is set to true in sadis config for VoD and VoIP service for a subscriber (this is needed for mac-learning in the future - but currently we hardcode mac address for these services). 
As soon as DHCP flow is pushed down an ACL to trap DHCP packet is installed on the PON port. This inadvertently results in DHCP packets of HSI service being trapped to ONOS when it is supposed to actually trace the HSI flow path to reach the BNG/DHCPServer.
When ONOS receives a DHCP packet for HSI service it complains that it is not expecting to see the DHCP packet with c-vid (HSI c-vid) and drops the packet. This means the HSI client does not get an IP.
Surprisingly we are consistently seeing this issue now and we never really observed this problem before.