No CUDA events were collected, multi-gpu system profiling

I have the following issue: I have to do some profiling on a Windows machine with 4 K20c GPUs. The drivers version is 430.86 (CUDA 10.2). I installed several versions of Nsight Systems (2019.1, 2019.4, 2020.4) and ran the profiling, but it only shows the CPUs, saying there’s no CUDA events. However the application does run CUDA kernels. What could be a reason for this? Note that I cannot connect via ssh, so I am running on the machine directly.