Synergy won't let my PC be the Client

[Seratone 0]

After a recent shutdown my iMac will not accept connections from my PC - I can easily share my Windows 10 PC's mouse and keyboard - but not vice a versa.

I believe it's the config information presented by the PC the Mac's not accepting.

I've tried removing and reloading Synergy several times but the IP's remain in the config - how do I remove all traces of Synergy and reload it?