I get the issue without going anywhere near the sleeve. It seems to me that although shutting the screen sends the V to sleep, the keys touching the screen wake it up again (ghost touches?). And this doesn’t necessarily happen immediately - I’ve put the V to sleep (without case) then a couple of minutes later heard the “ding” of a USB device being added (the keyboard).
Mind you, I now have an intermitent (but now almost permanent) connectivity problem with the keyboard - I’ll contact support about that when I get a chance. Bluetooth is OK but if I can’t connect the KB I can’t charge it. Neither can I do anything which requires a keyboard to access the BIOS.