invalid root flags, have 0x400000000 expect mask 0x1000000000001

Good morning.
Following a failure of a synoligy NAS, the three disks have been removed and are in the tower of an ubuntu computer. The BTRFS raid is well recognized. But the mount command refuses to mount it with the referenced message.
This in ubuntu 18.04 and ubuntu 22.04 version.

I have four questions.
1) Is it possible to find a document that explains, in human language, the meaning of 0x400000000 and 0x100000000000.
I searched without finding. I saw a track referring to subvolumes (https://www.reddit.com/r/synology/comments/u6y5qm/has_anyone_found_a_solution_for_mounting_synology/)

2) The mount command has plenty of options, I couldn't find one to override. Did I search wrong?

3) I wanted to repair with the command
btrfsck (see attached file)
I probably misused the options.
I don't know if using these two options would be helpful
--init-csum-tree
--init-extent-tree

4) I hesitate to install an old version of ubuntu 14.04 or 16.04 because I fear that the mount command will start to loop instead of indicating an error or actually doing the mounting.

Thank you for your review and have a nice day.

==========================================================================
===> Extract of journalctl when mounting is asked

juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS: device label 2021.01.13-18:19:28 v25426 devid 1 transid 2952074 /dev/md2 scanned by mount (11373)
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS info (device md2): using free space tree
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS info (device md2): has skinny extents
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS critical (device md2): corrupt leaf: root=1 block=77758464 slot=0, invalid root flags, have 0x400000000 expect mask 0x1000000000001
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS error (device md2): block=77758464 read time tree block corruption detected
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS critical (device md2): corrupt leaf: root=1 block=77758464 slot=0, invalid root flags, have 0x400000000 expect mask 0x1000000000001
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS error (device md2): block=77758464 read time tree block corruption detected
juin 01 00:15:21 jeanyves-HP-Compaq-6005-Pro-MT-PC kernel: BTRFS error (device md2): open_ctree failed

====> The return of the first repair command
sudo btrfsck -s 1 --check-data-csum --repair --progress /dev/md2
using SB copy 1, bytenr 67108864
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
Starting repair.
Opening filesystem to check...
Checking filesystem on /dev/md2
UUID: ff6851ee-a74e-4839-a08b-31bf0c91f44f
[1/7] checking root items (0:00:02 elapsed, 84719 items checked)
Fixed 0 roots.
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)00 elapsed, 26 items checked)
ignoring invalid key
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
...
...
...
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
super bytes used 3524243456 mismatches actual used 3524210688ed, 2847 items checked)
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
...
...
Invalid key type(BLOCK_GROUP_ITEM) found in root(202)
ignoring invalid key
No device size related problem found (0:00:07 elapsed, 5461 items checked)
[2/7] checking extents (0:00:07 elapsed, 5696 items checked)
[3/7] checking free space tree (0:00:00 elapsed, 328 items checked)
[4/7] checking fs roots (0:00:01 elapsed, 1914 items checked)
[5/7] checking csums against data (0:00:05 elapsed, 4453 items checked)
[6/7] checking root refs (0:00:00 elapsed, 124 items checked)
[7/7] checking quota groups skipped (not enabled on this FS)
found 7048454144 bytes used, no error found
total csum bytes: 2311576
total tree bytes: 88965120
total fs tree bytes: 63143936
total extent tree bytes: 17842176
btree space waste bytes: 23227198
file data blocks allocated: 17847271424
 referenced 14762950656

====> The return of the second repair command
sudo btrfsck -s 1 --tree-root 202 --repair --progress /dev/md2
using SB copy 1, bytenr 67108864
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
Starting repair.
Opening filesystem to check...
ERROR: tree block bytenr 202 is not aligned to sectorsize 4096
Couldn't read tree root
ERROR: cannot open file system