Gluster USER SERVICEABLE SNAPSHOTS: Cannot see `.snaps` directory

Sorry for disturbing you... Uh, I met a very strange GlusterFS problem: I can access snapshots by using FUSE mount and it works fine. However, when I test Gluster USER-SERVICEABLE snapshots feature, I find I cannot see .snap directory in the NFS shared directory. So pls help me solve this problem, many thanks~ My Gluster version is glusterfs 8.6. My OS version is CentOS 7.9.2009

[root@pgsql-1 media-cifs]# gluster v info disperse_vol_2

Volume Name: disperse_vol_2
Type: Disperse
Volume ID: a8bd1d15-20c0-43af-a66e-eb166bd92f4c
Status: Started
Snapshot Count: 5
Number of Bricks: 1 x (4 + 2) = 6
Transport-type: tcp
Bricks:
Brick1: pgsql-1:/run/gluster/snaps/1c51095f455d4b93b1dd2fcfdfdb6127/brick1/data
Brick2: pgsql-2:/run/gluster/snaps/1c51095f455d4b93b1dd2fcfdfdb6127/brick2/data
Brick3: pgsql-3:/run/gluster/snaps/1c51095f455d4b93b1dd2fcfdfdb6127/brick3/data
Brick4: pgsql-1:/run/gluster/snaps/1c51095f455d4b93b1dd2fcfdfdb6127/brick4/data
Brick5: pgsql-2:/run/gluster/snaps/1c51095f455d4b93b1dd2fcfdfdb6127/brick5/data
Brick6: pgsql-3:/run/gluster/snaps/1c51095f455d4b93b1dd2fcfdfdb6127/brick6/data
Options Reconfigured:
features.show-snapshot-directory: on
features.snapshot-directory: .snaps_disperse_vol_2
features.uss: enable
storage.fips-mode-rchecksum: on
transport.address-family: inet
nfs.disable: on
features.quota: off
features.inode-quota: off
features.quota-deem-statfs: off
features.barrier: disable
snap-activate-on-create: disable
cluster.enable-shared-storage: enable

Here is the snapshot info:

[root@pgsql-1 media-cifs]# gluster snap info snap_disperse_vol_2_test1
Snapshot                  : snap_disperse_vol_2_test1
Snap UUID                 : 8cab3954-3055-43aa-b34f-bbff58375881
Created                   : 2021-12-21 09:23:43
Snap Volumes:

        Snap Volume Name          : 4dd90c9a08f1449fb865a368676ebd61
        Origin Volume name        : disperse_vol_2
        Snaps taken for disperse_vol_2      : 5
        Snaps available for disperse_vol_2  : 251
        Status                    : Started

But I can not see any .snaps directory in the media3 directory.

[root@pgsql-1 media-cifs]# mount -t nfs 10.10.10.1:/disperse_vol_2 /media3/
[root@pgsql-1 media-cifs]# ls -a /media3
.       21.txt  24.txt  27.txt  2.txt   32.txt  35.txt  
..      22.txt  25.txt  28.txt  30.txt  33.txt  36.txt   

I can access snapshot by using FUSE mount and it works fine.

[root@pgsql-1 media-cifs]# mount -t glusterfs 10.10.10.1:/snaps/snap_disperse_vol_2_test1/disperse_vol_2 /mnt/snap/
[root@pgsql-1 media-cifs]# ls /mnt/snap/
20.txt  23.txt  26.txt  29.txt  31.txt  34.txt  37.txt  3.txt   42.txt  45.txt  48.txt  50.txt  7.txt
21.txt  24.txt  27.txt  2.txt   32.txt  35.txt  38.txt  40.txt  43.txt  46.txt  49.txt  5.txt   8.txt
22.txt  25.txt  28.txt  30.txt  33.txt  36.txt  39.txt  41.txt  44.txt  47.txt  4.txt   6.txt   9.txt

I haven't any clues to solve this problems, pls help me. tks~