Hello @WRD2093AU
Just a couple thoughts here. First, while Nest WiFi does provide clients with some extra information they can use to make better decisions about which band to connect to, which access point to connect to, and when to switch, clients are still in charge of those decisions. Worse yet, many clients ignore the extra information Nest WiFi provides (since the 802.11k and 802.11v specifications are optional). So, if your laptop is connecting to 2.4GHz, it is because it has decided that is the best option. That could be because it isn't doing a great job of making that decision, but it could also be because there is a source of 5GHz interference nearby that is making 5GHz a poor choice. Things like wireless gaming headsets and wireless subwoofers / surround sound speakers can all cause these issues, since they often use the same part of the 5GHz spectrum, but not using a WiFi-compatible channel structure. I've even seen cases where someone had a wireless internet service provider that was interfering in that part of the band. Oddly, it's also possible to be too close to the access point. If you're within three feet, it could be a problem. So, I would investigate this angle to see if you can figure out what may be happening.
As for beacon interval, that is a network-side configuration, not something client devices can change. In some very high density environments (e.g., enterprise / office), it can make sense to use a longer beacon interval just because there are so many access points all beaconing at the same time. But, in a home environment, even with a few secondary mesh points, the standard beacon interval shouldn't be a problem. This also shouldn't have any impact on which band a device selects, since beacons are sent independently on both bands. I'm curious why a client device would even have a configuration setting for this, unless it is part of some internet connection sharing feature where it can act like an access point, or maybe WiFi Direct?
