Postgres: ERROR: operator does not exist: point <@> point

Using PostgreSQL 11 on Windows.

Both cube and earthdistance installed and verified by pg_available_extensions.

Restarted PostgreSQL.

[42883] ERROR: operator does not exist: point <@> point.

Setup:

CREATE EXTENSION IF NOT EXISTS cube SCHEMA temp;
CREATE EXTENSION IF NOT EXISTS earthdistance SCHEMA temp;

Tried the following code from StackOverflow

create table temp.lat_lon (
  city varchar(50) primary key,
  lat float8 not null,
  lon float8 not null
);

insert into temp.lat_lon values
('London, GB', 51.67234320, 0.14787970),
('New York, NY', 40.91524130, -73.7002720);

select
  (
  (select point(lon,lat) from temp.lat_lon where city = 'London, GB') <@>
  (select point(lon,lat) from temp.lat_lon where city = 'New York, NY')
  ) as distance_miles;

Throws:

[42883] ERROR: operator does not exist: point <@> point.

Extensions installed and Postgres was restarted.

select * from pg_available_extensions where name IN ('cube', 'earthdistance');

cube            1.4     data type for multidimensional cubes
earthdistance   1.1     calculate great-circle distances on the surface of the Earth

Is this because of PostgreSQL v11 on Windows? Yes, Lat/Long in correct order (long is first).

Note: Table F.6 Point-based Earthdistance Operators

Update in regards to: schema / search path:

SELECT extname, extnamespace::regnamespace FROM pg_extension
WHERE  extname IN ('cube', 'earthdistance');

cube            temp
earthdistance   temp

SHOW search_path;

temp

Note: I CREATE EXTENSION hstore SCHMEA temp; and can use hstore and its operators. So doesn't seem to be all extensions.