The earnings from the WETH Vault can take up to 3 days to show up in the vault. However, it is important to check the Yearn Watch website for harvests to ensure that the earnings have been correctly credited. The website will provide a detailed breakdown of all harvests, as well as the total earnings for the vault. It is also important to remember that the earnings from the WETH Vault are not guaranteed and can vary depending on the market conditions. Therefore, it is important to monitor the vault's performance to ensure that it is performing as expected.