100% incompatibility

I’m running ZeroTier 1.12.2 on a Mac. I also have an NVR on the local network. Both ZT and the NVR operate perfectly normally independently. However, as soon as I try running them at the same time the one running completely freezes up/non-responsive until I disable the other - these two cannot operate simultaneously and I have no idea why. As soon as one is disabled the other continues normal operation as if nothing happened. The NVR is an Amcrest NV4108E-A2 (web interface uses port 80). When ZT is running and the NVR web interface is inactive any ping to the NVR is a 100% timeout - but, again, as soon as ZT is disabled, NVR functionality returns/pings are normal. Any idea what this might be, or any workaround for this might be? (I have placed the NVR at multiple IP addresses with all the same results.)