If a block explorer says the transaction is confirmed and it's not showing in Poloniex it's probably an issue at their end.
I once had a decred deposit not show up there, their support form has an option for missing payments, mine was credited correctly within 24 hours of reporting it.
I once had a decred deposit not show up there, their support form has an option for missing payments, mine was credited correctly within 24 hours of reporting it.
Thank-you for confirming my suspicion. I submitted a ticket yesterday with Poloniex once noticing the issue.