This looks like a correct behavior on UEFI installations.
People usually fail to understand that UEFI is NOT DYNAMIC, meaning: when you have a UEFI boot set to Windows it will always boot windows. When you set UEFI boot to Linux, it will always use Linux. Another thing to remember is: systems don’t control UEFI boots, UEFI settings do that so basically - it’s up to you to set or create an UEFI boot you need.
Basically what you need is just a Linux UEFI boot, because Grub can recognize both systems so you can choose which one to boot (manually or automatically), while Windows UEFI boot can’t do that directly and will boot only Windows.
Now the other hard part is: each BIOS/UEFI firmware does it differently preventing from writing nice tutorials. Because of that everyone skip that part and users are left clueless.
Here are examples:
- My old lenovo laptop showed automatically Manjaro boot and allowed me to set it, but didn’t know the right path to EFI folder with boot file, so on first boot I was given error and some commandline UI to browse EFI and choose the right path to boot file. Since I was clueless at that time I tested it by trial and error till I found the proper path.
- My current computer doesn’t show automatically any new UEFI boot but has option “add new” where I can choose the path and name the new UEFI boot (which I named simply Manjaro) and then I can choose it.
There are some workarounds to this but proper dealing with it is understanding what you are doing and simply setting correct UEFI boot.
If you manage to boot a Grub and you don’t see windows, run Linux and update grub by:
If everything is fine, Windows should be visible in Grub the next time you boot.