I'm having an issue with DHCP on Raisecom ISCOM HT801-GSFP SFP+ ONU.

The port is set to trusted in DHCP & PPPoE Snooping settings and I get all the packets both ways through the SFP+ module except I don't receive DHCP offer.
So it works with manual IP settings, but DHCP doesn't work because response from ISP doesn't reach my router.

The module itself works in a bridge mode.

I believe this is a bug that should be fixed, I have no other explanation.
Reached out to support email 4 days ago, but no response.