This is normal. An inference engine needs support for a model's particular implementation of the transformer architecture. This has been true for almost every model release since we got local weights.

Really good model providers send a launch-day patch to llama.cpp and vllm to make sure people can run their model instantly.

It isn't about normal or not. It is that those patches are done for Nvidia, but not AMD. It is that it takes time and energy to vet them and merge them into those projects. Kimi has been out for 3 months now and it still doesn't run out of the box on vLLM on AMD, but it works just fine with Nvidia.