Hiya! Which CUDA miner version are you using? Some of the links in this thread are outdated and point to the first experimental builds of the community CUDA miner.
I released a new build 1-2 days ago which has a lot of speed, reliability and usability improvements. You might give it a try: https://bitbucket.org/LieutenantTofu/cosmic-v3/downloads/

Repository for the "2.10.0pre5" CUDA miner on which it's based: https://github.com/azlehria/0xbitcoin-gpuminer

MVis' Tokenminer also supports mining on CUDA GPUs, but not as fast. But, it also supports OpenCL(AMD, CPUs) quite nicely:
https://github.com/mining-visualizer/MVis-tokenminer

Seconding that #support on the Discord is a great go-to if you have any problems: the people there are super helpful and friendly.
Good luck and happy hashing