My latest TF in Win 10 expects cudnn64_7.dll. If I copy the latest cudnn64_8.dll as cudnn64_7.dll, I get an error.
The solution is not to cut corners and install the older CUDA DNN (cudnn-10.1-windows10-x64-v7.6.5.32) together with the corresponding older CUDA framework 10.1 (cuda_10.1.243_426.00_win10), which is still the latest currently supported by the most recent TF 2.2. That combination works.