Raid 1 fails on Reboot

Hello,

I purchased server from OVH and they provide 2x960 GB ssd nvme for system storage and 2x1.92 tb ssd nvme storage extra. Now I installed Almalinux 8 OS on 2x960 ssd nvme and everything works fine. Now when I create single partition on 2x1.92 tb ssd nvme and convert it to Raid 1 then on reboot raid 1 fails and removes one drive from array automatically. Now when I create 2 partition on 2x1.92 tb ssd nvme and convert 1 partition to Raid 1 on reboot everything works normally and fine. Was I doing wrong by creating single partition and converting it to Raid 1 or its a bug?

What process did you follow to convert a partition to raid1?

mdadm --create /dev/md/md4 --level=1 --raid-devices=2 --name=md4 /dev/nvme2n1p2 /dev/nvme3n1p2

Are you putting anything in /etc/mdadm.conf?

yes the details of raid. I did everything correctly.