Have some more info.
[manjaro@manjaro ~]$ sudo btrfs check /dev/sda2
Opening filesystem to check...
Checking filesystem on /dev/sda2
UUID: 17243299-2eab-4c05-9d27-76b0968b95e5
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
block group 237318963200 has wrong amount of free space, free space cache has 4096 block group has 1073737728
failed to load free space cache for block group 237318963200
[4/7] checking fs roots
[5/7] checking only csums items (without verifying data)
[6/7] checking root refs
[7/7] checking quota groups
check/qgroup-verify.c:546: account_all_refs: BUG_ON `ref->num_bytes != num_bytes` triggered, value 1
btrfs(+0x1a65d)[0x55b57c0f165d]
btrfs(qgroup_verify_all+0x5ad)[0x55b57c0f27ad]
btrfs(+0x49d9a)[0x55b57c120d9a]
btrfs(main+0x8e)[0x55b57c0ed0be]
/usr/lib/libc.so.6(__libc_start_main+0xd5)[0x7fdc46329b25]
btrfs(_start+0x2e)[0x55b57c0ed3ee]
Aborted
[manjaro@manjaro ~]$ sudo btrfs check --repair /dev/sda2
enabling repair mode
WARNING:
Do not use --repair unless you are advised to do so by a developer
or an experienced user, and then only after having accepted that no
fsck can successfully repair all types of filesystem corruption. Eg.
some software or hardware bugs can fatally damage a volume.
The operation will start in 10 seconds.
Use Ctrl-C to stop it.
10 9 8 7 6 5 4 3 2 1^C
I did not coninue with the repair because of its warnings. Maybe try something else first??