Varifier doesn't always trigger

[CC007]

Varifier doesn't always seem to correctly trigger.

It does work for:

Optional<Integer> test = Optional.of(1);

But not for:

var optInt = Optional.of(1);
Optional<Integer> test = optInt;

And also not for:

private static Optional<Integer> getOptInt() {
    return Optional.of(1);
}
...
Optional<Integer> test = getOptInt();

Using the following versions:
Java: 25.0.2
Gradle: 9.4.1
Errorprone: 2.50.0
Errorprone gradle plugin: 5.1.0