Windows 10 + Manjaro + Manjaro, grub only shows 2 OS

I had installed Manjaro about a couple of year ago. Later, installed Win10. At that time successfully recovered GRUB as Manjaro instruction. Yesterday, I installed another Manjaro on a different partition. after reboot, Grub showed me Win10 and old Manjaro. so I loged in to old Manjaro. I ran

grub-mkconfig -o /boot/grub/grub.cfg f

After reboot, Grub shows new Manjaro and old Manjaro. And there is no Win10. What could I try to solve this problem? Thank you.

I have 4 partitions on sda
sda1 windows10 <— This is not shown on boot
sda2 old-manjaro
sda3 swap
sda4 new-manjaro