I'm on Mac OS and it was no problem for the camera and microphone!

Microphone and sound output usually also work via HDMI, but perhaps a driver needs to be updated. Alternatively, you can also check the privacy settings; I recently had problems with this in the office because the microphone wasn't working in Teams. You can find the privacy settings in Windows 10 by clicking on the Windows icon in the taskbar, then clicking on the gear icon for the settings and selecting "Privacy".

Have you connected the monitor to the computer with a usb-c cable? That's the only way it works for me (I first used an HDMI cable), but otherwise I don't have any other tips, I'm also a layman