Intellij warning about a null check after a SoftAssertion

Question

I have some tests in which I've created multiple validator functions that run several assertions on each test case. I've set up these validators to have an instance of SoftAssertions that is passed to each one, and assertAll() is called once all of the validator functions have run. For one of my validators, I have the following assertions:

TestArtifact artifactA = testArtifacts.getArtifactA();
softAsserts.assertThat(artifactA)
    .as("TestArtifactA should not be null")
    .isNotNull();

if (artifactA != null) {
    softAsserts.assertThat(artifactA.getTimestamp())
        .isEqualTo(expectedTimestamp);

    // additional assertions omitted
}

It's my understanding that, since SoftAssertions will only fail a test case when the assertAll() function is called, the null check above is necessary, in case the above SoftAssertion is false. However, in Intellij, I'm getting a warning message on the if statement, saying:

Condition 'artifactA != null' is always 'true' 

I've confirmed that the warning goes away if the isNotNull() soft assert is removed. Is this warning just a false alarm from Intellij? Or am I missing something about SoftAssertions that actually makes the null check after the assertion unnecessary?