It's probably easier to assign a fixed address to the PC, and item you will not be moving around to another location like a laptop. Choose a high address, out of the DHCP range set on the hub, something like 192.168.0.200. Then if you have to pin hole reset the hub at anytime you do not need to update it. On the PC just go into the network settings with the IP address you choose, DNS server of the hub, 192.168.0.1 and mask of 255.255.255.0.
There are 10 types of people: those who understand binary and those who don't
Well I finally managed to sort it a long winded way. Because it takes so long to scrape the shared media for the android tv box I was reluctant to change to another new IP address.
My PC did have the starting address (192.168.0.10).
I made a note of the MAC address and before turning the pc on for the day I connected to the router wirelessly from my mobile. My pc was showing in the list, tried to refresh but as the IP lease hadn't expired, it remained. So in Advanced Settings > DHCP, I changed the starting address to 192.168.0.11. This then released the lease on 192.168.0.10.
I was then able to reserve the address with my PC's mac address. First time I tried to apply the changes it failed with an error. Tried again and the new rule was added. I then changed the starting address back to 192.168.0.10. The address is now reserved.
If I ever change Android tv box I will do what Tudor recommended and reserve an IP address for my pc as a high number that won't get used easily if I have to reset the router.
Why there isn't a check box under Connected Devices so you can reserve the current IP address to the current connected device, only VM knows.
Another really annoying thing is the time it takes for each page to open when in the Hub's settings. Chrome actually flashes up do I want to kill the page or continue to wait, it takes so long. sigh.
Thanks for the pointers guys, it helped to find a workaround solution.
This all sounds perfectly reasonable. However, even if I reserve an IP address for a particular mac address, the hub keeps changing it. It's almost as if the hub is ip-address-hopping. In my case I'm trying to allocate a fixed IP address for a TP-Link WAP that I'm using as a wireless bridge. The WAP is set to have a fixed IP address, but in the Hub 3's lease table, the IP address for that mac address keeps changing, even when I set it as reserved. I've never seen anything quite so bizarre. No, there are no other DHCP servers on the network. Even more bizarrely, everything connected to the WAP bridge is working and is connected to the internet, even when the Hub 3's lease table says that its IP address is something different from what it actually is.