+1
FYI, I've been running Channels DVR and PLEX on a Windows PC for more than 2 years now and I don't have any third-party antivirus software installed. I started with Windows 10 and later upgraded to Windows 11.
When I got this new computer, it came with a free trial of McAfee. The first thing I did was uninstall it completely. I hate third party antivirus software. They often make your computer bloated and they add hooks to many parts of your system.
As @speedingcheetah mentioned, I don't use my server to go to wild and potentially dangerous websites, or open shady emails. Similarly, I haven't used any antivirus other than the one built in Windows for more than 10 years and never got into trouble. My network is not exposed, there are no holes in my router firewall.
In my own experience, third-party AV software has caused me more trouble than helped me (false positive detections, blocking apps from accessing the network, etc.) No need for extra trouble.
Just my extra 2 cents.