I would like to ask for your advice regarding an issue I experienced today with my IVT PremiumLine E10 ground source heat pump, which has been operating reliably in my home for approximately 14 years.
Following a complete power outage at my house, I restored the main electrical supply. The main switch indicated that all three phases were present; however, the heat pump did not start. The display remained completely blank, the standby LED was off, there were no characteristic operating sounds, and the unit showed no signs of life.
After switching the main power supply to the heat pump off and on several times, the unit finally started normally. Since then, it has been operating as expected. I also checked the event/error log, but no new errors had been recorded.
This situation has concerned me, especially because the unit appeared to be completely unresponsive after the power was restored. I would therefore appreciate your advice on what could have caused this behavior.
Is this a known or typical phenomenon with the IVT PremiumLine E10? Are there any components or settings that I should inspect, or any preventive maintenance you would recommend to

avoid similar situations in the future?
Thank you in advance for your time and any guidance you can provide.