I also lost my session settings a few weeks ago on 1.2.4 beta after simply turning off my H9000, and then turning it back on a couple of days later.

I had been tweaking the same session for some time already, and this had never happened before. I don’t remember if the fx chains were all empty afterwards, or if some default factory session was loaded instead, but still, all of my session settings were lost. Saved sessions were however intact in my H9000, so I was able to load a previous saved one. I’m in a habit of saving everything after doing major changes, but still I hope this was only a single incident and won’t happen again. I’m now on 1.3.0 beta. So far so good. 

BTW, is there some kind of a battery inside the H9000 that deflates over time if not connected to AC power? I’m using a main power switch to turn on/off my gear and started wondering if I should keep the H9000 connected to ac and use it’s own power button instead? Don’t think so but let me know if I’m wrong.