With all respect. Should I wait for a follow-up or I should consider this case as closed?

Please note that:

• There is a single user accessing the socket dir (which is the same as the homedir).
• The socketdir (homedir) is not in a local directory. It is in another file system accessed via the SMB protocol, with a command such as:

gpg --homedir "//192.168.32.211/c$/gpghomedir" ...

From the '&ovl' I assume that the lock file has been opened for overlapped IO.
Please see an extract from MSDN for the LockFileEx function:

Yes it is the windows version. It occurs both in Windows 10 and Windows Server 2016.
What I notice is that a gpg-agent is started, then after some time another one is started and the previous ends (presumably because it has lost the socket), etc. At any point in time, I can see only one agent instance running in the task manager, but with different process ids.