LED staying on after first relay trigger
If using a solid state relay, consider such a device may rely on driving a load using AC rather than DC.  That is, the solid state relay my not turn off until a zero crossing occurs.  Solid state relays intended to switch DC driven loads are normally designed using MOSFET switches.  Solid state relays intended to switch AC driven loads are normally designed using SRC or TRIAC switches.  Read more about this here.