Does my energy monitor have a problem?

This is a repost; as my 1st post didn't get any helpful answers. I have a 2005 Toyota Prius with 192k miles. Both batteries are almost new with the hybird battery being an OEM replacement with less than 70k miles. I had to take my car in due to it dying in a freezing snow storm. The car was checked and both batteries are in good shape. The issue turned out to be the ECM which was fixed. The car runs and drives fine now but my energy monitor doesn't behave like it used to. Before the ECM failure issue, my battery gauge on the monitor would reach all the way to the bottom until it turns red and then the gas engine would charge the battery on the monitor and raise it by a bar or 2. Now my energy monitor freezes about halfway and won't go to the bottom. Also, there are times when I hear the gas motor running but no activity arrows showing on the screen. Is it possible that something was not plugged into the 12v battery? It sounds like it could be a temperature sensor but IDK if the gen 2 has that like the gen 3. Any advice would be appreciated.