Apple TV does support Sound on Lenovo ThinkVision P24h-20 but cannot change sound level via remote control

I have a Apple TV 4K device with the newest remote control available. I can use this Apple TV with my Lenovo ThinkVision P24h-20 monitor connected via HDMI. The speakers are detected and I do have sound. Unfortunately, I cannot change sound level with the remote control. However, once I add my bluetooth box for the sound I can change the level with the remote control. This workaround is useful, but could you please fully support ThinkVision monitor devices? Another hint: my monitor supports USB-c which is great for my laptops. It would be fantastic if Apple TV devices would support this port as well.