1.What is the DHCP range setting in your router. If you have set a static IP address within that range you can get an address conflict and fail to connect. It would be best to set the static address outside the DHCP range.
2.You probably used a browser on your phone to try and access your router and what you probly saw was the retained history from a previous connection.
3.My old android phone does not show a WiFi symbol if it fails to connect, it initially shows the symbol but if it does not connect to the network it disappears.
If your router is a HH6 go to Advanced settings> IPV4 and check the server range. the default is 192.168.1.64 to 192.168.1.253 and it is not advisable to set a static IP address within this range due to conflicts.
If you give your phone a static IP outside the DHCP range it will always use this address on this router and will not show up in the DHCP lease table.
I don't have a Hub5 so see here for example
All static addresses should be listed in the home Hub and you will be able to add and remove as you see fit.
its a hub5. how can you set it outside the range and still connect to the router? and how would i know another device is not doing exactly that and not visible to me
The range is the DHCP range not the whole subnet that can be used and you should know waht addresses are being used on what devices because you would have to have manually set them.