7490 new 07.60 firmware slowed down my fiber internet

I have a 500mbps symmetric fiber internet connection with a fiber router from my isp, which is connected to my FritzBox 7490 via LAN1 to provide the internet to my network, and it was all fine until 2 days ago when I installed the latest 07.60 firmware for the fritzbox, now my speedtest is capped at 50mbps download/100mbps upload.

The fiber modem still tests as 500/500 but behind the fritzbox it became much slower.

Tried to change the settings, remove the power consumption saving thing, still nothing more than 50mbps download.

Any idea how to fix it? can I go back to the 07.59 firmware with the recovery exe firmware? I have a copy