Very VERY high probability of a bad switch or if the wires connect to the switch with slip-on connectors (faston) a bad connection at the faston terminal.
TAKE AN IMAGE or THREE of the switch before you start transferring wires. Like what was pointed out above the wiring pattern is not easy to memorize and if you pull on one wire and Oops three wires come off....you are in for quite a journey.
Use a GOOD quality switch. They are called DPDT center-off, momentary action. A cheaper switch will inevitably fail with the slide-out "almost all the way in or out" Murphy At Work.