I had an almost same issue OP mentioned. I had difficulties only using my mouse was over Horizon Client on Mac. The problem is LAGGING. Maybe somebody dealt it as a tiny problem but that is crucial problem for me since I took a lot of my working time in Horizon Client Environment.
My environments are:
- MacOS (High Sierra)
- Horizon Client Version : I tested every recent releases(4.3.0, 4.4.0, 4.5.1, 4.6.0, 4.7.0) but all versions have same issues
- Mouse : Logitech MX Anywhere 2 (via bluetooth connection)
I consider it as a temporary behavior because it worked perfectly when I connect via Horizon Client on Windows 10. But it happened every time I used it on Mac.
I have an idea by reading this thread. Maybe problem is in a mouse or a monitor. I tried to change my connection between mouse and Mac from via Bluetooth to via Unifying (provided with the product), and the lagging hasn't happened so far.
Thanks for OP.