Help with Kia Hybrid

Hi everyone I have a 2017 Kia Optima Plug-in Hybrid. The check engine light was on so I had a mechanic come look at it and run the diagnostic codes. He said the entire car died while he was doing so. That had never happened before. He jump started the battery under the hood, and car ran fine the whole day. The next day- car is dead again. When I try to jumpstart it, engine turns on but ALL of the alerts pop on the dashboard. Anyone have any idea what may be wrong?