both SO and me are in Europe, so it is the morning here
I attached a photo to try to make it easier to explain, if you shunt to the end of the green arrow, it should register as long as it is connected, if you shunt to the blue arrow, it should only register when the key is pressed, else it is one of the solder remnants on your board that is shorting something, or that your switch got overheated when you soldered and melted inside.
and a thing that can work to remove excess solder is to use a wet sponge to clean the tip of the iron (when hot, if you have a simple non controlled iron, may be up to 500°C) and remelt the solder on the board, although it will damage your tip(thermal shock) and may damage the board, if you have house wiring lying around, the flexible kind, you can also use that to soak up the solder (remove some insulation 1st though, and not when it is in use, i am talking scraps or leftovers), less damaging to the iron