Sound from mic is playing, but not recording

[jazzlessjazz]

I checked all settings and everything should be right. QuickTime is recording my mic, but OBS Studio not.
What should I do? How can I resolve this problem?

 

[AaronD]

The Monitor output here is for headphones or studio monitors. The Output goes to the Tracks selection.

If you're using the Simple Mode, then you only have Track 1, so make sure you're sending to that one.