Inside is there a pull latch to release the boot? Usually if you pull the seats forward and fold them down, there should be some sort of pull latch attached to the boot lid, which releases it. Idk if your car has that but it’s worth having a look,
I recently bought a iMac 2011 with the same issue. One thing that helped me is taking the plug out, waiting 10 seconds, pressing the power button for 10 seconds, waiting another 10 seconds, then plugging it back in, wait 10 seconds and turn it on. Now the fans spin and disk drive made a noise, so i know it’s working but no display so still yet to fix it properly. Maybe you might have more luck with that! Also i have heard a pvram reset helps. But it requires a usb keyboard.
One thing to try, is the filter empty? On the base corner of your washer there should be a flap, with instructions of how to empty the filter, maybe there is a clog that’s stopping it from working. Has a error appeared on the screen when it stops?
It sounds weird but is there some debris blocking it from fitting properly? Have you placed the filter the right way around? I do not own one of these but i had this problem with a vacuum i have used. Hope it works!