Altcoin (Litecoin fork) creation. No synchronisation i m trying to create an altcoin from the current Litecoin master branch on github. Its Litecoin in the version of 0.15.1.

By editing some parameter in chainparams.cpp i m able to create my genesis block. But i cant get the network to synchronize!

I m running litecoind on a vps with all ports open, and i am able to connect to the node when i start the litecoin-qt on my machine (with -addnode or -connect to the vps). 

On my vps i can see my machine with -getpeerinfo and its block count (0).
On my machine i can see that it is connected to the litecoin node on my vps.
When running generate on my vps, to create some blocks, i can even see on my machine, that the block count of my vps has risen. Still, there is no synchronization! The blockchain on my machine stays 0.

The litecoin-qt on my machine shows me "Connecting to Network" all time, even though it is connected to the litecoin node on the vps.

In chainparams.cpp i have edited the following sections:

pchMessageStart:

    pchMessageStart[0] = 0xf1;
    pchMessageStart[1] = 0xc0;
    pchMessageStart[2] = 0xb6;
    pchMessageStart[3] = 0xd0;
    nDefaultPort = 9333;
    nPruneAfterHeight = 100000;


and the genesisblock:

genesis = CreateGenesisBlock(1512851040, 376896, 0x1e0ffff0, 1, 25 * COIN);

and the checkpoint (the genesis block i created):

      checkpointData = (CCheckpointData) {
        {
            {0,           uint256S("0x6213f0e07c17e4ccef1fd9d023b06ce7e8bdbddaf2c4175197149302b7c351e8")},
        }
    };

    chainTxData = ChainTxData{   
        1512851400, 
        500,  
        0.06    
    };


Anything else is unchanged! Ports, etc. are alle the same as with Litecoin!
Please help. debug.log shows no errors. Took different approaches with -listen, -server, -deamon and of course a .conf file. Nothing seems to help.
This is the last step of my first chapter in blockchain development :)
remove the chainTxData


chainTxData = ChainTxData{   
    0, 
    0,  
    0    
};



and make sure also that your first block is mined soon after the genesis time.