I have ~12 DSP-W215s that I've purchased over the years. Recently, with the last two software updates, the devices have been showing their configuration SSIDs even after configuration is completed. Any WIFI device in the house can connect to these SSIDs, phones, computers, etc., though no internet connection is provided once connection is established. You can imagine how noisy the WIFI has become in the house with 13-14 devices trying to act like WIFI stations simultaneously. Airplay to my Apple TV hardly works anymore, and it's rare that we get through a hour of Netflix or any other streaming video or audio without drop-outs, and this on a 2.4 + 5GHz WIFI router that runs 60 Mbps.
I need to add that the devices are all recognized by the Dlink application. They turn on and off when ordered and seem to be working fine, other than the fact that they have accessible SSIDs and are cluttering up channels in the house.
My router is the Giga-router supplied by Verizon FIOS, now part of Frontier FIOS. It's about 2 years old.
What's frustrating is that all the SSID seem to go into hiding like they're supposed to sometimes, like after a software update. Then they start popping back up. The most recent example occurred after a power outage that took down the FIOS power supply and thus the internet for a day. It took a day for Frontier to fix the outside power supply and get internet back up and running. In the mean time, all the SSIDs showed up. When Internet was restored, the SSIDs didn't disappear after the devices connected.
I've reset and reconnected one of the switches. That SSID went away, then a couple hours later it came back. There was an interesting event during the connection programming when the DLINK iPhone app supplied my primary WIFI SSID and password automatically to be used by the DSP-W215, I accepted it, then I got a screen telling me to try a different WIFI. I put in the credentials for my lower power WIFI that I use for security cameras, but the DSP-W215 wouldn't connect, so I reset and connected to the primary WIFI once again, this time without issue.
It's frustrating, and I wonder what sort of security hazard it poses. I'm unplugging all my DSP-W215s until this issue is sorted out.
Note that I'm not having troubles with the 50 or so automated devices that reside behind my Wink hub, and my 3 Alexas work fine. My DLINK 932 security cameras are fine, as well as my Ring security cameras.