Why does a gigabit switch give out no more than 100 mb / s?

Question

network hardware

I see a strange sight. Gigabit switch 10/100/1000 mercusys ms105g, 5 ports.
At the input there is an 8-core patch cord with a gigabit connection (I connected directly, measured it on speedtest). At the output, I planned to connect several devices to the switch to use the speed of 100+ mb / s
But, for some reason, the output does not exceed 100 mb / s. How to achieve gigabit output on all other devices (PC) connected to the switch?

All patch cords are qualitatively crimped and successfully individually pass gigabit through themselves (I tried to connect directly, from the router, bypassing the switch.
Network cards of gigabit devices successfully support.

Answer 1

It helped to change the speed in the settings of the network card (in the device manager) from automatic to gigabit.
For the answer - thanks to Andrey
Barbolin

Answer 2

One question and it is most likely the answer - does the router support a gigabit WAN port? look in the admin panel of the router what it says about WAN
I doubt that a consumer router is capable of NAT-it gigabit, it needs a good processor.
ps gigabit routers give gigabit for local network, incl. to the router (for example, if you put a disk for files in it)