Hi @Goblin12345, welcome to our forums!
Are you measuring these speeds with a wired connection or over Wifi?
What issues are you running into with the TV? TV should work just fine with 30Mbit/s.

Measures via WiFi and cable.  Today there was a technician from the KPN and everything is fine.  Speed ​​is still slow l. It has already dropped to 13 Mbps

That's not good. I'd love to take a look at your connection.
Could you update your profile and let me know?

Already updated. Today, my internet speed is 10 Mb / s and my wages for 50 Mb / s are getting lower every day

Thanks for the update @Goblin12345, I see there's another technician coming tomorrow. 
Let us know how that turns out!

So was the technician. He fixed the problem. But today the speed has dropped to 22 Mb / s again

Good afternoon @Goblin12345. That's a shame! I'm reading there was something wrong with a cable. I really hoped that would've fixed the issue.
I took a look at the connection and it's unstable still/again.
I made a new ticket for my technical colleagues. They will contact you about this.