valid/invalid custom select reverts to default border color on focus

Created by: tmorehouse

Version: Boostrap V4.0.0-beta.2 Browser: Any OS: Any

Custom select border color, when valid or invalid, reverts back to default (non-validated) blue border color while focused, although box-shadow coloring is correct In this example I am using classes .is-invalid and .is-valid on the custom select.