OSPF route in database, but not in routing table? (LSA-7)

Hi There, an OSPF troubleshooting question here.

Issue: An OSPF NSSA area sees a default route in the database but that route is not being injected in the routing table.

I've checked that the NSSA forwarding address in the LSA-7 is reachable and not learned through an external route which would cause issues (see Why Are Some OSPF Routes in the Database but Not in the Routing Table?) and everything seems okay there.

The set up is as following: The ASBR, which is also an ABR, is redistributing into OSPF a default route. The forwarding address in the LSA-7 is seen across all the area and the forwarding address is set to that ABR+ASBR router loopback interface. So far everything seems correct.

How to reach that loopback interface is learned through OSPF intra area routes (i.e. non-external route) that means the entry in the database should appear in the routing table - but it does not.

Question: How do I continue troubleshooting what might be wrong with this route that should appear in the routing table but for some reason it is not?