The Surface Pro 7 is one of Microsoft's latest 2-in-1s. Some people who have bought it have subsequently gone back to the Redmond giant's product forum reporting a bug in which the tablet shuts off without warning. The issue may be addressed with some work-arounds, but the OEM is apparently yet to issue an official fix.
https://www.notebookcheck.net/Surface-Pro-7-users-are-reporting-random-shutdowns-and-that-Microsoft-has-done-nothing-about-it.461707.0.html