Your battery monitor numbers look pretty good... If you click upper left corner and go into "special features" you can read and clear battery error codes, as well as engine error codes. Once we know the error codes and how long it takes for Red Triangle to come back we can help you out.
The master warning light (sometimes called, overdramatically, the "red triangle of deeeeeeaaaaatthhh") illuminates for a couple hundred different reasons that are identified by diagnostic trouble codes. Without those, it can be a fun game to guess at why it might have come on, but only if you haven't got anything else to be doing. Only some of those codes even have anything to do with the battery. Unfortunately, the only screenshot I see here is from Dr. Prius, which will only even show trouble codes from two or three of the dozen different ECUs in the car. (It just shows "engine codes" and "battery codes". If it showed "hammer codes", it could make every problem look like a nail. Or if the problem wasn't a nail, it just wouldn't show you the code.) There's a recent thread where mr_guy_mann reviewed a bunch of different apps to see which ones would give the most useful troubleshooting information for Gen 2. There might be one you could easily download and even use with the same dongle you are using with Dr. Prius.
Maybe this is where having some electrical background comes in handy. For a typical DIYer, looking at a block voltage graph while the HV battery is in a 'charging' condition is a waste of time. Everything looks good when it's being charged. I can drain a module down to one volt, start charging it, and within seconds, it will be back in the 7.x range If you want to get a good look at HV battery condition, use the Hybrid Assistant app and do a HV battery test using the AC system in the car. The AC system can load the HV battery at 8-14 amps and the app will log all block voltages. Start the test with the car fully warmed up so the engine stays off and all power will be supplied by the HV battery. The engine will start when the battery is around 42% SOC , so I typically stop the test around 43%. The app can then be used to graph the voltage logs. It will display all 14 blocks so you can see exactly how each block tracks. Easy squeezy. I'll attach a thread that has some of these graphs so you can see what they'll look like. Just Another HV Battery Thread and Experiments | PriusChat
