I have set up my own testnet. When I generate a new wallet by using
monero-wallet-cli --testnet --restore-deterministic-wallet and providing a seed, it works as expected. Wallets receive both mined and transferred coins.
However, if I create a new wallet using
monero-wallet-cli --testnet in an empty dir, the new wallet doesn't see any incoming transaction and balances are 0/0.
refresh command doesn't help.
Then I issue
seed command, copy the words away, exit client, delete all wallet files and start again by
monero-wallet-cli --testnet --restore-deterministic-wallet and paste the seed I copied. Suddenly, the wallet now refreshes transactions as expected an calculates its balances properly.