Problem with Avg function and Money type in PostgreSQL 15

CREATE TABLE Product(product_id SERIAL PRIMARY KEY,
price MONEY NOT NULL);

INSERT INTO Product(price) VALUES (30);
INSERT INTO Product(price) VALUES (40);

SELECT Avg(price) AS av FROM Product;

PostgreSQL 14.5

ERROR: function avg(money) does not exist
LINE 1: SELECT Avg(price) AS av FROM Product;
HINT: No function matches the given name and argument types. You might need to add explicit type casts.

PostgreSQL 15

ERROR: stack depth limit exceeded
HINT: Increase the configuration parameter "max_stack_depth" (currently 2048kB), after ensuring the platform's stack depth limit is adequate.
CONTEXT: SQL function "avg" during inlining
SQL function "avg" during startup
SQL function "avg" statement 1 --this line is repeated more than 3000 times

It seems to me that PostgreSQL 14.5 response is much better than in case of PostgreSQL 15.

Best regards
Erki Eessaar