[Ethereum] Uniswap Approve Succeeded But No ETH Returned in “Swap”

erc-20-approvefailed-transactionuniswap

I attempted to swap some eMax (using the Uniswap Swap feature) for ETH and the Approve went through, in the end I received another token (old version of token before hard fork).

It seems to be the correct token address, I seemed to have had enough ETH for gas, what happened here?

https://etherscan.io/tx/0x4808b55c6f49a377697016b1e94787c4688e196c076cc495e1383fc46d7c3008

After further research after first posting this, I realized the token I received was an old version of the eMax token before a hard fork. I never purchased/traded this token. I just received the old token of eMax in this swap transaction. How is this even possible with Uniswap swap contract? "New eMax" for ETH and receive another token? Aren't the only possibilities here that I receive ETH or nothing if the transaction fails?

https://etherscan.io/token/0xa3e059c0b01f07f211c85bf7b4f1d907afb011df?a=0x9448ec46932ef1647c332a80c1e782a239f97523

"Other" eMax

Did I do something wrong? Am I misunderstanding something? How can I prevent something like this in the future?

**edited to emphasize that I used the swap feature of Uniswap and received verification of swap with transaction address and clarification that I received old version of the token I was swapping instead of ETH

Best Answer

The transaction that you made is only the approve function. Basically, you are giving the permission to Uniswap to take eMax tokens from your account and do anything they want with it.

After that approval, you have to send the actual swap. Check the Uniswap interface again and the button should have changed from approve to swap. You only need to approve once per token. You do not need to approve when you are swaping Eth for a token, so that's why the Eth->eMax swap did not need an approval transaction first.

As for the fact that you have eMax tokens twice in your account, they are actually two completely different tokens that are both called eMax (this one, and that one). The owner of the eMax tokens sent you the tokens of the second eMax contract about a week after you purchased them with the first swap.