Slow EA-AC87

Hi forum

I am new here inside and I hope to get help from you guys.

I have installed an PE-AC88 in my PC. WIth my former ISP, I reached in AC 5GHz mode almost 900 MBit/s ( It is an 1GBit/s connection), which is quite good for Wifi.

Now, after changing the ISP, I am running an FritzBox 5490 as Modem. I connected a EA-AC87 in AP mode ( Firmware Version:3.0.0.4.374_2849) .

If I connect my PC with Ethernet to the AP, I...

Slow EA-AC87