I found a related issue on upstream git. https://github.com/lxc/lxd/pull/11333 Following date of 5.0.2 and issue creation. This fix is not present on 5.0.2.
- Bug#1032482: LXD - issue with btrfs backend loop file Sylvain Tgz
- Bug#1032482: Sylvain Tgz
- Bug#1032482: LXD - issue with btrfs backend loop file Mathias Gibbens
