COPY FROM appears broken in PostgreSQL 15

Did something happen to the COPY FROM command in PostgreSQL 15?

I used to run scripts to process and load data from files into various
PostgreSQL tables. A series of:

copy {schema.table} from '/{path}/{file}' delimiter '|' null '' ;

in PostgreSQL 15 it fails with this message:

ERROR: could not open file "/{path}/{file}" for reading: Permission denied
HINT: COPY FROM instructs the PostgreSQL server process to read a file.
You may want a client-side facility such as psql's \copy.

I have checked and the postgres user can read/write to the file just fine.

In PostgreSQL < 15 it works just fine.
The official PostgreSQL docs, up to and including 16, don't mention a
problem with this command.

Did something happen?

Thanks,
rik.