@N-Gen Welcome to the Rockstor community. My main concern is the SMR drive. Please see this post which details these concerns re btrfs on these drives. Short of it is they are known to the btrfs developers and there is work yet to be done to support their unique way of working.
The random ID as a disk / dev name is what Rockstor gives “missing” drives which is consistent with your finding that it falls from lsblk visibility, ie it no longer appears to be connected.
Hope that helps, but it looks like you are going to have to consider using another or better still several other drives, you will at least then gain redundancy which is a key feature of btrfs. These drives are very different from all that have come before them and need special treatment from the underlying OS; unlike all that have come before them in this regard. I would say the short coming is more in their reliance of offloading their responsibility to that of their connected OS. Not a fan myself as they seem like too much of a hack / push of the technology.