The LCD micro is specially made to work with 4 or 8 bits, (read the data sheets), as you specify that when you define your LCD pins etc.The LCDout command if using 4 bit mode actually sends the 8 bits as 2 4bit nibbles.

Your current item will not understand - hence garbled etc.

Your new unit is NOT compatible with LCD commands, and no where does it mention 4 bit operation, as I said, get it working on serial, if you use the data bus you will have to have at least 10 ports to run it in that mode.