Problem with g raid thunderbolt 3

Hello,

I ve got a problem with my G raid. i ve got two hard drives in it.
one light of the hard drive is blue and the other one is red.
I tested the both hard drive (together and indivudaly) on my mac and they are working, no problem
If i removed the blue light, the red light hard drive become blue.
I think the hard drivers are going well but i don’t understand why the color of the light indication change
when i restart the g raid or when i removed one hard drive…

I think i have to do a resynchronization of the hard drive. Can you do that without erase the both hard drive ?

Someone have a idea ?

Best,