Synergy is Freezing on Ubuntu 18.04 Client with Win 7 Server

Conditions:

I have a Window 7 machine with Synergy configured as a server sharing the keyboard/mouse with an Ubuntu 18.04 client. TLS is not enabled. Ubuntu client is 1.8.8-stable+dfsg.1-1build1. Windows server is 1.10.2-stable-8c010140.

Problem:

When the mouse is hovering over the Ubuntu desktop area, and I am navigating with the server's keyboard, selecting files, entering and exiting subdirectories, opening files, etc., the keyboard and mouse periodically freeze for several seconds. The occurrance is random but fairly frequent.

Additional Info:

If I keep trying to do keyboard operations while the freeze is in effect, when the freeze ends, it seems as if the keyboard activity is buffered and the undisplayed keyboard actions are then played until the end. This suggests that the freezing is somehow caused by the Synergy client running on Ubuntu. If I turn off the synergy client and server, and use the Ubuntu client keyboard and mouse to do the same operations, no freezing occurs. This suggests that the issue is related to Synergy, not the desktop environment in general.

However, this started happening after I upgraded the client from 16.04LTS to 18.04LTS. I have had to resort to using the installed keyboard on the client machine and, unless this is fixed, I am at the point that I am considering refunding my paid subscription to Synergy.

Is this a known bug? Is there a fix or workaround I can apply? Any help would be greatly appreciated.