This message was posted on behalf of Intel Corporation
Thanks for posting. We understand that you would like your systems to connect to wireless on 5GHz band only.
Please notice this is not considered an issue from the wireless adapter or driver side. Even though you may tell the adapter to prioritize a band, the disposition of the bands and the actual network management is done by the router or access point.
Reading the release notes for the latest Intel wireless adapter drivers, there's no mention of changes involving band preference. However, we recommend to update the driver on at least one of the systems for testing.
The best approach would be to either review the router settings or disable the 2.4GHz completely.
Please let us know if there's anything else we can do for you.