Installed in BIOS mode as per your sda layout.
That’s normal, as the Windows 10 UEFI files do not exist and you cannot mix BIOS and UEFI installs.
Now you need to put the machine in BIOS mode to boot to Windows and in UEFI mode to boot into Manjaro.
The solution without having to change the boot mode, you ask???
- Delete Manjaro and install it in BIOS mode too and
grubwill find Windows in BIOS mode…
OR - Delete Windows and reinstall it in UEFI mode
Note: Just in case you re-install, ensure the following lines are present without a # on the second line in /etc/defaut/grub:
# Uncomment this option to enable os-prober execution in the grub-mkconfig command
GRUB_DISABLE_OS_PROBER=false