already I have sent them ticket couple days ago, they answered me on 19 Sep. :  "Unfortunately I can not give an ETA on this being enabled at the moment. It has been disabled by Management for wallet maintenance issues. I am sorry for any inconvenience, but we do hope to have this issue resolved as soon as possible."

I did some research, found that coin is also listed on another exchange where all works fine: https://novaexchange.com/market/BTC_BTM/

... so if client working well, chain is moving, transfer works between wallets (tested by my self) - no any technical issue at all - I see no reason why poloniex disabled BTM transfer since so many days.     

"... wallet maintenance issues" - really !?!   how long it takes to restart client, resync with network etc... couple hours max. not weeks!!! Unless there is other reason for that...