So this started about a month or so after I purchased my Netduma (roughly two months ago). I had originally attributed it to issues with my wifi, then my modem. It wasn't very often, and rebooting everything did the trick.
It's started to happen much more frequently, going from once a day or so, to a few times a day, and now it's happening a few times a session (ex after dinner till bedtime).
Aside from changing the anti-flood sliders and host filtering options, my settings haven't changed.
The tell for me is that I can restore the connection to both wired and wifi devices by changing any setting in anti-flood. For example, simply moving the sliders, or changing from preemptive to reactive (and vice versa) will all restore connections.
I have my device prioritization set to 100% for my Xbox, and share excess enabled.
My Xbox is the only wired connection, and it loses connection the same time as all wifi devices.