@vonklars I found it, it was in QOS which has a "Total Bandwidth". It was still using the old speed, even though it said "Via internet speedtest". Setting it to manual and to 500/500 solved the issue.

Hi, I have a new Fiber Internet connection and when I test: - without a deco router in between it is: 500Mbps up and down - with a deco router in between and via the deco app: 500Mbps up and down -...