Having been through something similar VMware will ask you to do the following.
Build a vanilla master image from a ISO and only install Windows updates, VMWare Tools and the Horizon Agent.
If you don't experience the issue slowly add software to your image until you determine what the problem is.
If you do experience the issue with a vanilla image make sure your hardware BIOS/firmware/drivers and ESXi are current.
If you continue to experience the problem open a SR with VMware.