Why constant current LED mini spot flickering after connecting to constant current LED driver?

For all constant voltage LED driver, the output voltage is not fixed, it is in a range, only the output current is fixed.  All the mini spots must be connected together in series with LED driver, and each mini spot is 3V-3.2VDC input, all the mini spots total voltage must be in the range of LED driver.  If it is too low or two high, the LED mini spots will flickering or burn out.