Need Help Understanding Unusual Clicks in DV360/CM360 Campaign Reports

Hi everyone, I'm relatively new to DV360 and CM360 and could use some assistance! I'm currently analyzing a completed campaign that recorded an unusually high number of clicks. From my experience, this could indicate bot traffic. I want to investigate further to identify the source of these clicks so we can mitigate this issue in future campaigns. I've put together several reports in CM360 and noticed a lot of clicks categorized under 'Not set' and 'Unknown'. Can someone explain what these labels mean? How can impressions be served to unidentified locations or users? Are there any specific reports or strategies you recommend to help me dive deeper into this issue? Any advice would be greatly appreciated!