Do you have a decent quality 10Gb NIC? The reason I ask is you describe a result that is similar to software-driven NICs. Especially where turning off the SW firewall helps. That kind of hints that your NIC is CPU constrained, where a 10Gb NIC definitely needs hardware offload to function well. With...

Are the cameras 1Gb eth, or 100Mb eth? Understand that unless you have a pretty high end switch, the more 100mb ports talking the more bandwidth you're going to lose across the switch fabric due to rate conversion. Most consumer-grade and even SMB switches aren't going to have any sort of fancy buff...

My H264 cameras do not seem affected by this in any way. Are you using the most basic H265 from the cameras ? Avoid any H265+ or souped up version, as it won't be so compatible with BI5. If not, set one to H264 and see what happens. I'll be honest and say I'm not the best with video encoding flavor...

Suddenly have this issue with 5.5.2.x as well. Specifically my H265 cameras will show loss of signal and stay in no signal. Restarting the camera does not help. I have to completely restart Blue Iris in order to reconnect them. As best I can tell when they disconnect in BI, there is no issue with th...