No connection when mixing cat5e and cat6?

Question

My home network looks like this:

internet => rg6 => modem => cat6 => cat5e => router => ...

router => cat5e => devices (OK)
       => cat5e => cat6 => switch => cat5e => devices (OK)
                           switch => **cat5e** => cat6 => cat5e => devices (BOOM)

The reason for mixing cat6 and cat5e is because the cat6 cables go through the walls and are terminated in a keystone, which I then connect cat5e cables to. For the last row at the top figure, my macOS laptops show self assigned IP addresses and cannot connect to the internet. Is there something I'm missing? My switch is a Netgear JGS524 if that matters.

EDIT: If I switch the cat5e above to another cat6, I can get internet on my macOS laptop, but the switch is showing my speeds as 100M instead of 1GB?

Answer 1

If I switch the cat5e above to another cat6, I can get internet on my macOS laptop, but the switch is showing my speeds as 100M instead of 1GB?

Something in the whole chain is degrading the signal quality so much that your particular cat6 cable works, while your particular cat5e cable doesn't. (One reason could be that your particular cat5e cable is faulty).

Check the whole chain for bad contacts, bent cables etc. Check that the connections are correct (match colors). Having an ethernet cable tester helps.