R80.20 - OSPF adjacency only sends host

[Alex-]

On my side: Checkpoint 5800 (non VSX) and R80.20 Take 33. Other side: Cisco router

I'm trying to announce a local route via OSPF. I activate OSPF on the interface connected to the router (Area 0) and redistribute the local interface containing the network I want to announce. Alternately, I add a static route to NULL with my prefix and redistribute that route.

In both cases, the peer tells me they briefly sees the prefix, then after only the /32 address of the interface my side. If I switch between the redistribution methods, this repeats. They have no inbound filtering of any sort, just plain OSPF in area 0.

Since it was to set up a production network we didn't have much time to dig in deeper and moved on to classical static routing. Does it ring a bell to anyone?