You have two bad lights, LED lights in spas come with either 2-way up to 6-way (2 to 6 light per strand). The strands can be a pain to change but most of the time you can cut and splice new lights on without changing the whole strand.
The LED lights do not get out of sequence, each point of light has three colors (red, blue and green) and one color is out.
Also the LED's are very reliable, it is odd to have them fail. Check the lenses to see if there are any cracks in them, if so replace those also are the lights will fail again. the cracks will let water through and that is what kills the lights.
