is this a known issue.. ? I had to save the file, close KS, open KS load file and then switch to GPU.
There is nothing specific that has been reported. There were quite a number of performance improvement for GPU in 9.3. If you can reproduce the crash, please send the crash log and file the issue at the link below and it will get channeled to the development team for review:
https://luxion.freshdesk.com/support/discussions/forums/60000205413