If you have internet over coax table with white adapter Teleste EOC05 and internet is unstable - just change your Teleste EOC05 to GIGA Copper G4201C (or similar, but this one is tested trust me).

Hot take, but now comes proper description with prehistory.

I live in an old house where it is not possible to drill new holes for more cables like cat6. Hence, I had to call KPN engineer who sold me a pair of Teleste EOC05 and internet got working. Happiness drove me crazy, but after a week I noticed that even though it is working, I still had freezes during online meetings, I have loads of them since I work from home only. In the evening I noticed that streaming videos are also throttling, whatsapp calls quality not as good as I was expecting from fiber, but I though that might be problem on another end.

Many circumstances were screaming that something is wrong with my internet and I started digging. My main concern was that linux ping tool gave me 4mc between my pc and router on the ground floor. I was shocked, even my mobile had less between amsterdam server. Second concern is that the same ping gave me from time to time between 3% and 30% packages loss.

Unfortunately there is not many review on the internet, not specifications and tests about Teleste EOC05 which made me even more suspicious.

Therefore I decided to buy a more expensive adapter and turns out my problem is gone now. I know my new transmitter is expensive (350 euros in comparison with 80), but I would really appreciate if I can be advised by KPN engineer between two options - one that will work and cheap, but not 100% work. And another options is quite expensive but always robust.

The goal here is to leave this topic in history for all the people who might experience the same.