[Samba] byte range lock for Write starting on Zero and negative length ( -9223372036854775808 )

[Antonio]

Dear All,

I'm sorry to bother the list with a problem that I am not sure 
originates in Samba.
File server (no domain) is serving a mix of Windows 10 and Centos 7 
clients, I have strange byte range locks.

- Server is Samba 4.17.5 / Kernel 5.14.0 Rocky 9.2

smbstatus -B gives:

- When client is Windows 10:
Byte range locks:
Pid        dev:inode       R/W  start     size SharePath               Name
--------------------------------------------------------------------------------
1551641    2431:14156401:0 W    1000013752 1 /home/geral/DAT          
APLIC/CC/ENCOMEND.DBF

- When client is CentOS 7 (Samba 4.10.16 / kernel 3.10.0)
Byte range locks:
Pid        dev:inode       R/W  start     size SharePath               Name
--------------------------------------------------------------------------------
1835914    2431:14156401:0 W    1000013752 1 /home/geral/DAT/APLIC/CC 
ENCOMEND.DBF

These are correct and the expected behaviour on both cases, files are 
shared and the 1 byte locks for ~write~are correctly honoured.

Problem is with new clients CentOS Stream (Samba 4.18.6 / kernel 5.14.0)
Byte range locks:
Pid        dev:inode       R/W  start     size SharePath               Name
--------------------------------------------------------------------------------
1832643    2431:14156401:0 R    0         -9223372036854775808 
/home/geral/DAT          APLIC/CC/ENCOMEND.DBF

The file gets locked for ~read~ starting at Zero and with a strange 
(negative) size. No other client can access the file...

The application is an "Harbour Project" production control, accessing 
many DBF/NTX files. It has been behaving rock solid for many years, many 
thanks to all the Samba Team.

Linux clients (Centos7 / Centos Stream ) access the server via automount 
cifs shares:
$cat /etc/auto.geral
   geral -fstype=cifs,rw,noperm,credentials=/root/smb.creds ://sol/geral

Windows clients access the server via normal network shares:
   net use f: \\sol\geral

The Linux executable is a single file served by the Samba server, so 
both clients (Centos7 and Centos Stream) use the same executable.

My question: Has anyone seen this before, and could kindly give any 
advice in which direction to search for a solution ?
I have searched the list archive, read everything related to "byte range 
locks" but found no clue...

Thanks a lot.
António Vila Chã