hi. i  have the same issue .  my 0,2 btc worth dgb didn't arrive from poloniex to my bittrex wallet for more than 12 hours..  tx id is not on block explorer.  at fist i thought it was a clogging issue but ten minutes ago i sent 1000 dgb from crytopia to bittrex and it arrvived. so this doesnt look like a clogging issue.