When you send a safe transfer, we actually transfer a slightly higher amount than what you originally specified to a hidden address . This is done so that we can pay the miner fees for the collect transaction once your recipient is ready to take your transfer. In other words, the actual transfer amount is original amount + future transaction fees.
When you retrieve the safe transfer back to your receiving address, we also have to pay the miner fees for this transaction. As you know, miner fees are dynamic in the Bitcoin blockchain and they can change from the moment of your safe transfer to the moment you are retrieving it.
So, the actual retrieve amount is original amount + future transaction fees – current transaction fees. If the current transaction fees are equal to the future fees that we’ve calculated during safe transfer, you will see the exact same transfer amounts on your device and in the web application. If not, there will be a slight difference in amounts.