If you’ve set a static address on your Nucleus, and your home network is no longer using 10.0.0.x addresses, then you need to reset your Nucleus network address like this:
Just an additional thought, if you are still using the 10.0.0.x address range in your home network, and you had set a static address of 10.0.0.121 in the Nucleus - have you got a clash because your DHCP server in your network has given this address to another device as well?