Netflix no longer opens on smart TV?

For a few days now, Netflix can no longer be opened on my smart TV. When I go to Netflix, the screen briefly goes black and then continues to play the normal tv program. The TV is new. I bought it new 3 weeks ago. It is from LG. Maybe someone can help me.

Wi-Fi ok?

Yes the Wi-Fi works. I can also watch Netflix on my cell phone. Unfortunately, I can't open this on the smart tv.