OpenCL with AMD RX 6900XT on Ubuntu 20.04

I have a fresh install of Ubuntu 20.04 (kernel version 5.8.0-50-generic) on a system consisting of an i9 9900K, an RX 6900XT and 32GB of RAM. This system is meant to run OpenCL code for a university project, preferably on the GPU. So far, i have installed the latest Pro Radeon drivers (version 21.10) using ./amdgpu-pro-install -y --opencl=pal,legacy, i have installed OpenCL headers using sudo apt-get install opencl-headers and i have installed ocl-icd-opencl-dev as well as cl-info and glmark. Using glmark, I can verify that at least my graphics card is correctly set up for running OpenGL. However, the AMD OpenCL platform contains no devices, i.e.

Platform Name                                   AMD Accelerated Parallel Processing
Number of devices                                 0

Is there anything obvious that I missed? Further information that may be useful: I have also installed pocl-opencl-icd which produced a working OpenCL environment and the Intel drivers for my CPU, which doesn't work at the moment (but might get fixed by fixing the AMD platform?) This installation is not dear to me, I just care for a running OpenCL installation. A fresh install of any other (free) distribution is fine with me, if this is easier.