I used this exchange a few years ago and never had any problems from my side, but don't know that now because I never use it anymore. And as @alastantiger said, according to the Poloniex Trustpilot page there are lots of bad reviews about them, even those reviews happened recently. So it's better to avoid this exchange, there are tons of better top-tier exchanges like Binance, KuCoin, Gate.io, MEXC and others.