What Happens if Stop Loss or Take Profit on Master Is Triggered but Not on Slave?

As soon as the StopLoss (SL) or TakeProfit (TP) is triggered, it will send a market order to close the Slave position. Even if the Slave does not copy the SL or TP in the account directly, the Slave position is closed when the Master position is closed.

This is why it is not necessary to copy the SL or TP on the Slave account to follow the Master strategy.

However, doing so could result in slippage, but it could avoid wrong trigger of the SL or TP on the Slave.