I have a TP Link router, Archer C9 v5, and I added two new switches to my network, TP Link SG105.  They are 5 port unmanaged switches, so I expected them to be plug and play.  Sadly the router is not recognizing either swtich on my network.

Here is what I have done:

1)  I power cycled both the router and the switches.

2)  I updated the firmware on my router.

3)  I checked both switches, and they have green lights to both the WAN ports, but none of the ethernet cables attached to the switches.

4)  I checked both switches, and when set up indpendent of my network, they can both ping between two comps set up independently, bascially I know they switches actually work. 

Here is what I know:

I know the LAN ports on my router work, since my main office comp is hard wired to it.  I know my wireless works on my router, because I have a dozen devices that work with my router.  I know both of my switches work when they are tested indepenently, but not when connected to my network.

Why can't my router recognize them and start giving MAC addresses to all of the things plugged into my switches?  I assume it's a settings issue with my router somehow.  Any ideas are appreciated.  I am not great with router and networking settings, so you might have to coach me through a few things on my router panel interface.

Thank you!