A simple Staking method, several bugs

Crypto-ERC20-DevToken-Stake-V1.0

contract DevToken is ERC20, Ownable {
    using Address for address;
    /**
    * @notice 
    *   This is a mapping where we store all Stakes that are performed on the Contract
    *   The stakes for each address
    */
    mapping(address => uint256) internal stakes;


    /**
     * @notice Wrap the ERC20 constructor with our own construtor, in this case we dont do anything but call the ERC constructor.
     */ 
    constructor() ERC20("DevToken", "DEVTK"){
        // Here we mint 100000 tokens to the account that creates the smart contract, 18 0s because ERC20 uses 18 Decimals 
        _mint(msg.sender, 100000);
    }

    /**
    * @notice
    * stake is used to make a stake for an sender. It will remove the amount staked from the stakers account and place those tokens inside a stake container
    */
    function stake(uint256 _stake) public {
        // Simple check so that user does not stake 0 
        require(_stake > 0, "Cannot stake nothing");
        // Make sure staker actually is good for it
        // Burn the amount of tokens on the sender
        _burn(msg.sender, _stake);
        
        // Add the stake to the stakes container
        stakes[msg.sender] = stakes[msg.sender] + _stake;
    }


}