Code:
nvme0n1p1 : isnotESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, BitLocker
nvme0n1p4 : isnotESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, BitLocker
sda2 : isnotESP, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, BitLocker
There are three partitions labelled BitLocker, which one has the (encryption) key when you boot Windows via Grub?