When I try to install the latest tumbleweed opensuse version, it restarts at the end. But when it turns back on, it’s back at the start prompting me to install it again! I don’t know how to fix this, I’ve tried installing it several times
Hi and welcome to the Forum 
I suspect the install media, did you try the option to boot from hard disk? If you remove the installation media, or go into your system BIOS and change the boot order, does this fix the issue?
Or have you by chance have a UEFI system and installed in Legacy(mbr) mode… or vice versa