Xendesktop 7.15, K2 - performance degraded

After an upgrade from XD 7.6 to XD 7.15 the performance of the desktop was significtif degraded. AutoCAD has mouse lags up to 15 seconds. We think the K2 support not all new features of XD 7.15. Does someone make the same experience?
Best Regards,

No, why should this be related to the GPU? Did you check if NVFBC is still enabled as example? There are for sure other issues than the GPU.