Nighthawk R7000 Networking Switch Won't work + 5G connection issues

> I am trying to use a new switch in my setup, but it does not work for
> any of my wired devices trying to use the switch. TP-LINK SH1008P 4 GB
> port switch. [...]

   So, you're having problems with a TP-Link switch, and you came to a
Netgear forum to ask about them?  An SG1008P seems to exist.

> [...] When I run a diagnostic check, [...]

   What kind of "diagnostic check"?  On _what_?

> [...] it says check your router. [...]

   Perhaps because that (unspecified) device can't talk to any router.

> Any settings / configurations on my router I should update? [...]

   No.

> Not when I plug one of my end computers into the switch, they cannot
> connect to the internet any more either.

   Huh?  "Not"?  What are "end computers"?

   If you connect a computer directly to an R7000 LAN Ethernet port, it
works as expected?  And if you connect a computer directly to a port on
the "SH1008P" is fails (in some mysterious way)?  And you blame the
R7000 for that?

   What, exactly, did you connect to what, exactly? (Hint: If a device
has different types of ports, then "connected to device" is not enough
detail.)

   Have you checked/swapped any Ethernet cables?  Do your computers get
valid IP addresses?  Do they admit to having a good physical link on
their Ethernet interfaces?

   Are there LED indicators on these devices?  What do they indicate?
For the R7000:

   Visit http://netgear.com/support , put in your model number, and look
for Documentation.  Get the User Manual (at least).  Read.  Look for the
LED descriptions and "Troubleshoot".

   For information on the TP-Link switch, you might take an
actual/accurate model number to "tp-link.com".