2015.5 xc60, single owner, engine replacement at 49K. The car has70K today and recently had rear bumper repair from rear end accident. We have a new issue that started afer body repair and the dealer has been unable to solve.

Occasionally, like every 15 days, after parking, the car does not have any electrical current, will not start, dashboard doesn't light up etc. If we wait 8 hours, the car starts again or if we disconnect and reconnect the battery terminals, it sometimes restarts faster.

The battery has only 15k miles on it, has a full charge, and is high quality. All terminals have been cleaned and wiring has been checked. It is like it takes a short rest break. The dealer said the issue was fixed but it keeps happening. Anyone have any ideas on how to investigate further? I would really appreciate any ideas.