I'm having the same issues on horizon client and web; remote desktops running smooth, low latency and great fps but only after doing the resizing. After you first connect it is stuck at ultra low frame rate. No updates happened (in regards to VMware products or Nvidia drivers) but this issue suddenly appeared. Can't seem to fix it with any settings I've tried so far. Did you ever find a solution for this? 

I also noticed in Horizon Performance Monitor the CPU encode usage is high when first logging in and its laggy. The CPU is usually under 1% for the encode but its around 3-6% on first login and after doing the window resizing it goes back to under 1% so seems like it may be reverting to CPU encode or something (one of the CPU cores is also locked at 100% utilization)