Currently I have to manually hit delete and boot from my Bios to get this working.
My Windows 10 install is on ├─sdb4 8:20 0 445.3G 0 part /mnt/windows
Sadly it does not come up with sudo os-prober either. Below is my lsblk
hutber@hutber:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 89.1M 1 loop /snap/core/8213
loop1 7:1 0 89.1M 1 loop /snap/core/8268
loop2 7:2 0 54.7M 1 loop /snap/core18/1650
loop3 7:3 0 54.6M 1 loop /snap/core18/1288
loop4 7:4 0 259.4M 1 loop /snap/acestreamplayer/9
loop5 7:5 0 259.4M 1 loop /snap/acestreamplayer/10
loop6 7:6 0 2.8M 1 loop /snap/pulseaudio/9
sdb 8:16 0 447.1G 0 disk
├─sdb1 8:17 0 450M 0 part
├─sdb2 8:18 0 100M 0 part
├─sdb3 8:19 0 16M 0 part
├─sdb4 8:20 0 445.3G 0 part /mnt/windows
├─sdb5 8:21 0 851M 0 part
└─sdb6 8:22 0 450M 0 part
sdc 8:32 0 7.3T 0 disk
└─sdc1 8:33 0 7.3T 0 part /mnt/xbox
sdd 8:48 0 7.3T 0 disk
├─sdd1 8:49 0 128M 0 part
└─sdd2 8:50 0 7.3T 0 part /mnt/tv
sde 8:64 0 7.3T 0 disk
└─sde1 8:65 0 7.3T 0 part /mnt/googledrive
sdf 8:80 0 238.5G 0 disk
├─sdf1 8:81 0 222.5G 0 part /mnt/oldlinux
├─sdf2 8:82 0 1K 0 part
└─sdf5 8:85 0 16G 0 part
sdg 8:96 1 3.7T 0 disk
├─sdg1 8:97 1 128M 0 part
└─sdg2 8:98 1 3.7T 0 part /mnt/downloads
sdh 8:112 1 3.7T 0 disk
└─sdh1 8:113 1 3.7T 0 part /mnt/jay
sdi 8:128 1 7.3T 0 disk
├─sdi1 8:129 1 128M 0 part
└─sdi2 8:130 1 7.3T 0 part /mnt/users
sdl 8:176 1 14.9G 0 disk
└─sdl1 8:177 1 14.9G 0 part /media/hutber/72AD-2013
sr0 11:0 1 4.1G 0 rom /media/hutber/MB Support CD1
nvme0n1 259:0 0 931.5G 0 disk
├─nvme0n1p1 259:1 0 450M 0 part
├─nvme0n1p2 259:2 0 99M 0 part
├─nvme0n1p3 259:3 0 16M 0 part
├─nvme0n1p4 259:4 0 247.4G 0 part /mnt/c
├─nvme0n1p5 259:5 0 11.2G 0 part [SWAP]
├─nvme0n1p6 259:6 0 10M 0 part
└─nvme0n1p7 259:7 0 672.4G 0 part /
