Internet connection "decays" on FTTH
I ran the SENSE router on my DSL connection for years with no problems.
Since a few weeks now I have changed my ISP to Deutsche Glasfaser on FTTH. My setup is SENSE - Ethernet socket - FTTH endpoint, automatic login without credentials.
Upon startup, everything is just great, I can measure my speeds at 400/2000 down/up as intended. But on the next day at the latest, I still have kind of an Internet connection. But everything is VERY much slower - page loading times. Gaming connectios etc. On my Smart TV, Netflix streams start and then start buffering, break off or the connection is lost completely. My VOIP landline phone still works. But e.g. Ookla Speedtest can't even detect an internet connection that it could measure. When this happens, when I check the networks status in my SENSE App, it doesn't display an WAN related info: gateway, IP, DNS - all empty.
I reboot the router, and everything is fine again... until the next day.
At the moment, I have made it part of my daily routine to just go down to my office, pull the cable and restart the router before trying anything internet related.
Is this a known issue? Is there anything that can be done about it?