I changed my SSIDs to separate the 2.4GB and 5GB WIFIs. I found that I couldn't get connected to 5gb on any of my Galaxy 7 phones or my new Samsung tablet. Looking at my firestick gave me the answer. The Verizon router changed my channel selections to automatic. I used an app called Wi-Fi analyzer. It showed the 5gb channel as 132. The firestick could not even see the SSID for 5gb. I set my channel to a lower number (36) and the firestick found the SSID and started working. Not only had that been fixed but, all the new Android Phones and Tablet worked as well.
Symptom: The phone trying to connect to 5gb just spins on connecting and never syncs. WPS will not work either.