If reconnecting the RDP session is a reliable trigger then we're definitely getting somewhere.
Please generate a VMMap trace (different to the VMMap snapshot posted above).
Using VMMap on the remote machine (where the leak is), starting the trace, then disconnect and reconnect the RDP session with the trace still running. If the leak is triggered while the trace is running then the trace should then tell us which EXE or DLL allocated the memory (and hopefully more).
Also, please let us know the details of the RDP set up (e.g. which resources the RDP client is configured to share between the two machines, and other RDP client settings; also the versions of Windows on each machine) so we can try recreating a similar setup.
It may also be worth checking if the problem depends on what is in the clipboard when you make the RDP connection. e.g. If there is a small amount of text in the clipboard, does it still happen? Or does it only happen if files are in the clipboard, or similar?