I just opened a ticket, but I wonder if somebody else encountered this?
Currently, this failed withdrawal is still shown as "COMPLETE" in my account, with tx id 777d943c86acf4ee22f65505f71732f00152d0af3b1b5ff7194292d46de212d3, which does not exist in the blockchain.
The answer 2 days ago to my ticket was:
"Hi binaryfate,
Okay, I will escalate your ticket to Tristan to resolve. Thank You and Warm Regards, Angela"
I commented 1 day ago:
"Any update?
I'm in touch with other people that were in the same situation, they received their withdrawals by now. What about mine?
I also have more to withdraw now. Please tell me asap if I can do it or if you are still resyncing.
Thanks for the work on XMR by the way."
I bought more later, and now I am scared to withdraw it that the same thing would happen.
I am starting to worry a bit, between that amount that simply disappeared and the second amount I have now but cannot withdraw, this is very significant to me.
Thought it was worthy for everyone to know, will update you.
Poloniex finally fixed this. They said after a reindex of the poloniex wallet they found that indeed my coins have never left them. They have sent me everything by now.
This is actually not their fault. The wallet is not mempool aware at the moment, so if a tx falls out the mempool (no miners mine it because maybe it's malformed or has the wrong fee or whatever) then the wallet doesn't know that those outputs are now unspent. It's on our list of things to fix ASAP!