My network consists of 2 XE75 nodes (one being the main) and 3 XE5300 nodes. I was noticing some odd disconnects periodically and read some posts that suggested setting statically placed devices to a specific node helped. After setting all these up, I did in fact notice less disconnects, especially on those devices. However, after upgrading the firmware to 1.2.3, it seems like connection preference is completely ignored. Devices will connect to any node as though they are set to auto. Forgetting the device and starting a fresh connection doesn't resolve the issue. 

Below is an example of my dryer that is specified to only connect to Kitchen, but is shown as connected to Basement. 

I do have an IoT network setup, and my main network runs on only 5Ghz. This problem occurs regardless of network.