Issues with grub

Hi, I recently bought a new PC desktop (CPU: Ryzen 2700X, GPU: GTX 1050ti) without any pre-installed OS. The PC had 2 SSD so I installed first Win10 and afterwards Manjaro KDE on the 2nd SSD. Upon installing Manjaro I created boot/efi partition and after 1 solid partition for root.
My problem is that when Bios boots in Linux SSD it doesn’t show Grub and takes me straight to initial screen. And 2nd when I did update grub it doesn’t recognize the other SSD as windows. So I’m left with the option to choose OS upon boot via bios selection. Any advice is highly appreciated. THANKS.