PARIS (AP) — French children, parents and teachers battled with internet connection problems across the country after an abrupt nationwide switch back to online learning after seven months of in-person class. Paris prosecutors opened an investigation into possible hacking into key systems. The education minister blamed overwhelmed private networks and servers for other bugs but frustrated parents are blaming bad planning. The government sent all France’s 12 million pupils back to class in person last September to reduce learning gaps. But France closed schools nationwide this week because of a new surge in infections fueled by the more contagious virus variant first identified in Britain.