I'm converting/testing the migration of a project that is using EF Core 2.1 to EF Core 3.1 and thus far all queries worked as expected, except one.
I had one query that suddenly uses an OUTER APPLY, but that is not supported in Oracle 11g. I think it should have generated a LEFT JOIN LATERAL in case the database version is 11.
At the moment it is a little bit hard to extract a simple example out of my code, but maybe you already have enough information. But if you really need it I can try to create a simple sample.
I'm using Oracle.EntityFrameworkCore 3.1.19.0 and the UseOracleSQLCompatibility has value "11".