This is a clear warning that the device has massive problems!
The last time I ignored such warning signs, it cost me more than 100€ for data recovery. It was still a spinning disk though. Since then I’ve been healed!
Since you are the admin:
Don’t repair, replace !
Most other file systems would only have reported this when data had already been lost! Because BTRFS writes (and checks) checksums, it notices the error IMMEDIATELY.
BTRFS will not allow you to write more data to a defective drive !
All data written before the message is normally intact (eventually do a btrfs scrub from within a live manjaro). But if the drive finally fails, there is no rescue other than the professionals (which costs a lot of money)
P.S.:
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You will be able to mount the filesystem readonly for recovery (with rsync)
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Or you could clone it with btrfs send/receive
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Do recover your data using a live manjaro (iso/usb). Not with your broken system !