Streaming at 60 FPS no longer possible, what to do?

I've been streaming (not known, but that doesn't matter) for a long time, and I've never had any problems. For a short time, however, for whatever reason, OBS has stopped receiving 60FPS, in the game I still have 100+ FPS without any problems. But in the stream there's no end: https://www.twitch.tv/...t=0h16m27s
Does anyone have a hint?
Info: 1 GB line
PC: NVIDIA RTX 2060
24 GB Ram
AMD Ryzen 7 3700X
If you still need something, let me know!

Is it not because of the game but your obs settings, what bitrate do you have when streaming? When you have the maximum rate, you still have to cut corners, you have to know what is more important to you. For example, to stream in Full HD or rather with many pictures, because you do not believe what the pixel quantities are that have to be sent to Twitch.

In the encoder you can also set a setting for better data transfer, for example, the CPU is then loaded more, but the encoder that passes it on works better.

Which settings are you currently streaming with?

Sorry if it's written a little wildly or confusing, I just woke up. ^^

Enoder - Hardware (NVENC)
CBR
6000 bit rate
2 sec keyframe interior wall
1080p / 720p
Profile - high
Default - quality
I just don't understand why a month ago everything stopped working.
Maybe more important - have a 240Hz monitor

Is everything up to date?

E.g. The graphics card? What does your process say in task manager?

Take times as a resolution of 900p.
6000 is too little for 1080p anyway.