One hardware issue seen with the new pre is that if you close the keyboard ‘firmly’ it seems to jiggle the battery enough that the disruption in power causes the pre to shutdown completely. One person’s fix was to put a piece of paper between the pre and the battery so its tighter. Another was to put folded electrical tape there.
Here’s a third idea. There is a tab in the pre when you open the back that you pull to get the battery out. If you fold that in half and replace the battery, you can still use the tab to remove the battery, and the folded tab is enough to ‘lodge’ the battery tighter in place so the shut-off doesn’t happen.