Hi can someone help explain this to me:

1) If i send USDC token from kraken to coinbase wallet (not coinbase, but its wallet app). It just cost me $2.5 and done.

2) But if i try to transfer USDC token between the wallet app's wallet1 to wallet2, it says it cost ether and is very expensive

I dont understand why coinbase wallet app transfer between your own wallets cost ether, while transferring the same USDC from exchange like kraken to coinbase wallet does not.