GS308E linked speed

Hello,

So I've a weird problem between two network switches.

My network setup is like this:

Modem <-> Switch 1 <-> Switch 2

Between switch 1 and switch 2 I have a 1000Mbps connection with all the old hardware.

Recently I decided to updgrade Switch 2 to the GS308E.

When testing the new GS308E I saw that the speed was reduced to 100Mbps and I can't understand why.

(Switch 1 is a TL-SG105E)

If there is somebody who can help me with this problem I'm glad to listen to the solutions.