Router not seeing 4 drives

[Spotmom]

I have a TPLink Archer C3150 router. When I hook the probox up to the USB3 port on the router it only sees the 1st drive. I have scoured the web for an answer. I see someone else says their router sees all 4 drives. Is there something I am missing?

[Admin_Mediasonic]

Most routers don't support Multi-bay enclosures.
that is why you see 1 drive only.