Please try installing nvidia-container-toolkit and restart docker daemon as instructed here (Should work for Ubuntu 19.04 too):
[url]https://github.com/NVIDIA/nvidia-docker#ubuntu-16041804-debian-jessiestretchbuster[/url]
Related issue and answer:
[url]https://github.com/NVIDIA/nvidia-docker/issues/1034#issuecomment-520282450[/url]