How to mock Prisma (via Proxy) in Jest 27

Our Prisma setup is as follows:

// server/database/prisma.ts

import { Prisma } from 'database/generated/prisma-client';

const client = new Prisma({
  endpoint: PRISMA_ENDPOINT,
  secret: PRISMA_SECRET,
  debug: PRISMA_DEBUG,
});

// Add a proxy 'middleware' to the Prisma client to record query execution time
const prismaProxy = new Proxy(client, {
  get(client, endpoint) {
    const endTimer = metrics.prisma_call_duration_seconds.startTimer({ endpoint });
    return function (...args) {
      const result: Prisma = client[endpoint](...args);
      endTimer();
      return result;
    };
  },
});

export const prisma = prismaProxy;

I then have a utility that uses prisma that I would like to test:

// utils.ts

import { prisma } from 'database/prisma';

export const myFunc = async () => {
  const result = await prisma.items();

  if (items && items.length > 0) {
    return true;
  }

  return false;
}; 

How do I mock prisma in a test? In Jest 26, this worked:

// utils.test.ts

jest.mock('server/database/prisma');

import { prisma } from 'server/database/prisma';
import { myFunc } from 'server/utils';

describe.only('my test', () => {
  beforeAll(() => {
    prisma.items.mockImplementation(() =>
      Promise.resolve([
        {
          foo: 'bar',
        },
      ])
    );
  });

  test('it works', async () => {
    const items = await myFunc();
    expect(items).toBeTruthy();
  });
});

This no longer works in Jest 27 it seems. Having made no changes except upgrading Jest from v26 -> v27 the mocks no longer seem to take hold.

What is the proper way to mock prisma here?