Win 10>OSX>RDP Windows - no SHIFT key

[patch 1]

As per the title I have a Windows 10 Pro running Synergy as server, this connects to a 2015 MBP on El Capitan. The MBP sits in two networks and I use that to RDP into the remote network to Windows systems. Synergy to the MBP works fine, I am writing this post on the MBP via Synergy and as you can see my ShIfT KeY IS wOrKiNg FiNe. The problem i have is that when I RDP from the OSX to a Windows machine my shift key doesn't work, most noticeable is that I cannot login as my password uses a capital and some special characters. This is Deeply Frustrating. I'm using the Microsoft RDP client from the Mac App Store. If I use the MBP keyboard and track pad everything works as expected. The Windows machines I'm RDPing to work fine from any other RDP session Frankly I don't expect Windows -> OSX to be a perfect translation via synergy but it actually works ok, its supremely annoying that it's hopping back into Windows that it all falls apart. I have considered using the Mac as the server and having briefly tested it it seems ok but that really doesn't fit my work flow and I'd have to make other comprimises to get that working, I'd prefer to be able to use what I've got. Any thoughts?

[patch 1]

Realised I never followed up on this. The issue is with Synergy's interaction with the MS RDP client on OSX, I had to purchase Jump Desktop from the App store to resolve the issue.