So I'm placing a 5x isolated leveraged trade in margin not futures on Binance. The liquidation price should be 20% from entry or max 15% max allowing for maintenance margin. But it's 8%. What? This works out the same if I use their margin calculator on any coin. 5x leverage = 8% from liquidation not 20%. This seems really odd and means there is no point doing leverage trades on Binance. Any explanations?