assertj: ZonedDateTime assertions are not consistent and don't expose isBetween

Summary

My test sometimes fails when the asserted value matches the (supposed to be inclusive) upper boundary. The example code fails with the exception:

java.lang.AssertionError: Expecting: <2019-03-04T10:22:45.622Z> to be between: [2019-03-04T10:22:45.622Z[UTC], 2019-03-04T10:22:45.622Z[UTC]]

Example

ZonedDateTime boundary = ZonedDateTime.now();
assertThat(boundary).isBetween(boundary, boundary);    // passes

ZonedDateTime actual = boundary.withFixedOffsetZone();
assertThat(actual.isEqual(boundary)).isTrue();            // passes
assertThat(actual).isBetween(boundary, boundary);         //fails