I had the same issue.
In short - there is a way to force GRUB to detect other operating systems.
Code:
$ sudo os-probe
$ sudo update-grub
$ sudo reboot now
There are few things to consider, the most important of which is the UEFI Boot of the BIOS.
I did have a KALI Linux installed as a solo operating system on this laptop (HP Pro Book 450 G7). I installed a new SSD with a Windows 11 and the Kali Grub did not detect it.
The reason was, that I did not have EFI partition on my Kali Linux installation.
I had to create that, it is just an empty partition about 100 MB size. Then make sure during installation KALI will use it as an EFI partition. That should be your boot-able drive.
In my case I have 1. NVMe2 drive with Linux and 1 SSD with Windows 11.
Your case may be different if you have only a single drive and separate partitions for your Linux and Windows OS. In such case you need only 1 EFI partition (one per physical drive).
I hope this information help you!
Kind regards!