Error: Not a Btrfs Subvolume: Invalid argument

[eode]

Rsyncing /boot into the filesystem before the call to timeshift.
Rsyncing /boot/efi into the filesystem before the call to timeshift.
Using system disk as snapshot device for creating snapshots in BTRFS mode

/dev/nvme0n1p5 is mounted at: /run/timeshift/backup, options: rw,relatime,compress=zstd:3,ssd,discard=async,space_cache=v2,commit=120,subvolid=5,subvol=/

Creating new backup...(BTRFS)
Saving to device: /dev/nvme0n1p5, mounted at path: /run/timeshift/backup
Created directory: /run/timeshift/backup/timeshift-btrfs/snapshots/2024-01-25_17-34-45
Created subvolume snapshot: /run/timeshift/backup/timeshift-btrfs/snapshots/2024-01-25_17-34-45/@
Created control file: /run/timeshift/backup/timeshift-btrfs/snapshots/2024-01-25_17-34-45/info.json
BTRFS Snapshot saved successfully (1s)
Tagged snapshot '2024-01-25_17-34-45': ondemand
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/dev/nvme0n1p5 is mounted at: /run/timeshift/backup, options: rw,relatime,compress=zstd:3,ssd,discard=async,space_cache=v2,commit=120,subvolid=5,subvol=/

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Removing snapshot: 2024-01-18_14-08-57
Deleting subvolume: @ (Id:266)
E: ERROR: Not a Btrfs subvolume: Invalid argument

E: Failed to delete snapshot nested subvolume: '/run/timeshift/backup/timeshift-btrfs/snapshots/2024-01-18_14-08-57/@'
E: Failed to remove snapshot: 2024-01-18_14-08-57
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This occurs when timeshift-autosnap-apt is triggered (manually or automatically). Clearly it's a misconfiguration, but do you have quick advice before I spend hours trying to figure it out?