Hardhat testing - revertedWithCustomError fails even though it matches the error thrown from contract

I am trying to write some unit tests for solidity contract. I have some functions that can revert with custom error based on the arguments provided.

function dissmissRegulator(address _regulatorAddress) public {
    if (msg.sender != s_regulators[msg.sender].regulatorAddress) {
	revert EMR__OnlyRegulatorsCanAddOrRemoveRegulators();
    }

    if (s_regulators[_regulatorAddress].regulatorAddress != _regulatorAddress) {
	revert EMR__RegulatorDoesNotExist();
    }

    delete s_regulators[_regulatorAddress];
}

This seemed simple at first, i just need to use to.be.revertedWithCustomError.

So I write this in my unit tests file

it("something", async function () {
    expect(await emr.dissmissRegulator(regulator))
        .to.be.revertedWithCustomError(emr,"EMR__RegulatorDoesNotExist");
});

I expected this test to pass, shouldn't be complicated.

But it doesn't. And the weird thing is console writes out this output:

 Error: VM Exception while processing transaction: reverted with custom error 'EMR__RegulatorDoesNotExist()'
    at EMR.dissmissRegulator (contracts/EMR.sol:81)

Now I am confused, why is the test failing when the error string in test matches the thrown error. Am I missing something? Is my logic flawed somehow?

await expect(emr.dissmissRegulator(regulator))
    .to.be.revertedWithCustomError(emr,"EMR__RegulatorDoesNotExist");

I awaited wrong expression