Logitech BRIO/BRIO 4K supports Full HD (1080p) video at 30 frames per second. If you’re not seeing 1080p resolution, it may be that your video conferencing application supports up to 720p or there might even be a setting within the application to put the video into HD quality entirely.  Please check your application requirements and settings. 
 
In addition, check the following:

• USB bandwidth — (ex. using many active USB devices at the same time)
• CPU utilization — (ex. file transfers, streaming, checking email, antivirus scanning)

Network bandwidth — your internet connection download speed should be at least 3 Mbps