Staking is not Haram as you put money into securing the network and validation transactions on the network. That's what staking is. You get a percentage of your share of what ever you put in to securing or validating transactions on the network. It's kind of like opening a ice cream shop, you only pay maybe 10 cents for a cone but charge the customer 50 cents. 10 cents being your investment and 40 cents is you securing a future for your business. You money is doing passive work for the network.