Issue description

The fee amount you have to pay for your ETH-based transaction changed while the transaction was being processed.

Resolution

We expect fees to fluctuate because we use an algorithm to calculate the fee and add additional fees as a delta in order to avoid transaction failure due to spikes or unexpected network behavior. This means that your starting and final transaction fees can be a different value when the transaction is complete.

During the signature process, the fee and gas can also increase. Our algorithm factors this into the calculation so that your transaction does not get stuck in the mempool if the fee increases. This is why the network fee is higher than the blockchain fee.

For example, on the Polygon network:

• Fees are paid in the network's base asset from its associated base-asset wallet. This wallet must have sufficient funds to pay the fee.
• Additionally, Polygon's priority fees can change rapidly.
• Therefore, we recommend using the High fee option to help prevent stuck transactions and causing an invalid fee error.