Hello,

In our case, after upgrading, all shares are able to connect (though it is 
done using anonymous user) but it fails to list with NT_STATUS_ACCESS_DENIED:

root@xxx:~# smbclient //192.xx.xx.211/Compartida -U xxx -p
Password for [WORKGROUP\xxx]:
Try "help" to get a list of possible commands.
smb: \> ls
NT_STATUS_ACCESS_DENIED listing \*

Tracing log debug it just reports the following:

2023/03/10 14:05:40.589326,  5, pid=2892249, effective(1000, 1000), real(1000, 0)] ../../source3/smbd/open.c:4621(open_directory)
  open_directory: Could not open fd for [.]: NT_STATUS_ACCESS_DENIED
[2023/03/10 14:05:40.589368, 10, pid=2892249, effective(1000, 1000), real(1000, 0)] ../../source3/smbd/open.c:6128(create_file_unixpath)
  create_file_unixpath: NT_STATUS_ACCESS_DENIED 
[2023/03/10 14:05:40.589488, 10, pid=2892249, effective(1000, 1000), real(1000, 0)] ../../source3/smbd/open.c:6316(create_file_default)
  create_file: NT_STATUS_ACCESS_DENIED

However, it does have permissions. Doing an inspection with strace, you can see
it can traverse directory needed, and open it, but it fails in a /proc/self
open operation:

>> strace -p <smbd process pid>
...
...
getegid()                               = 0
setgroups(8, [1000, 4, 24, 27, 30, 46, 116, 65534]) = 0
setresgid(-1, 1000, -1)                 = 0
getegid()                               = 1000
setresuid(1000, 1000, -1)               = 0
geteuid()                               = 1000
chdir("/home/administrador/Compartida") = 0
stat(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat("/home/administrador/Compartida", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
getcwd("/home/administrador/Compartida", 4096) = 31
getcwd("/home/administrador/Compartida", 4096) = 31
openat(AT_FDCWD, ".", O_RDONLY|O_NOFOLLOW|O_PATH|O_DIRECTORY) = 13
fstat(13, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
getcwd("/home/administrador/Compartida", 4096) = 31
openat(AT_FDCWD, ".", O_RDONLY|O_NOFOLLOW|O_PATH|O_DIRECTORY) = 44
fstat(44, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
openat(AT_FDCWD, "/proc/self/fd/13", O_RDONLY|O_DIRECTORY) = -1 EACCES (Permiso denegado)
close(13)                               = 0
fcntl(26, F_SETLK, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=36528, l_len=1}) = 0
fcntl(26, F_SETLKW, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=36528, l_len=1}) = 0
close(44)                               = 0
...
...

Here is our package list:

ii  python3-samba                         2:4.15.13+dfsg-0ubuntu0.20.04.1   amd64        Python 3 bindings for Samba
ii  samba                                 2:4.15.13+dfsg-0ubuntu0.20.04.1   amd64        SMB/CIFS file, print, and login server for Unix
ii  samba-common                          2:4.15.13+dfsg-0ubuntu0.20.04.1   all          common files used by both the Samba server and client
ii  samba-common-bin                      2:4.15.13+dfsg-0ubuntu0.20.04.1   amd64        Samba common files used by both the server and the client
ii  samba-dsdb-modules:amd64              2:4.15.13+dfsg-0ubuntu0.20.04.1   amd64        Samba Directory Services Database
ii  samba-libs:amd64                      2:4.15.13+dfsg-0ubuntu0.20.04.1   amd64        Samba core libraries
ii  samba-vfs-modules:amd64               2:4.15.13+dfsg-0ubuntu0.20.04.1   amd64        Samba Virtual FileSystem plugins