@gabor1, yes ESXi 7.0u3c resolves this VDI vGPU issue.  The release notes include:

• Virtual desktop infrastructure (VDI) might become unresponsive due to a race condition in the VMKAPI driver

  Event delivery to applications might delay indefinitely due to a race condition in the VMKAPI driver. As a result, the virtual desktop infrastructure in some environments, such as systems using NVIDIA graphic cards, might become unresponsive or lose connection to the VDI client.

  This issue is resolve in this release.