The problem here is that the DNS for the topology file incorrect.
Change the addr value in the testnet-topology.json from
"relays-new.cardano-testnet.iohkdev.io" - the difference being 'iohkdev' instead of 'iohk'.
'iohkdev' is for testnet and 'iohk' for mainnet.
You can check the testnet topology here: hydra.iohk.io/build/6498473/download/1/test..