The Mate 30 and Mate 30 Pro come in both 4G and 5G versions, with the "5G" provided by Huawei's Kirin SoC. Any time someone mentions "Huawei" and "5G" in the same sentence, know that they are talking about "Sub-6GHz 5G," which is completely different from the 24GHz-90GHz "mmWave 5G" currently being pushed by US cell carriers and Qualcomm. The higher frequencies of mmWave offer more speed but over a smaller range. So while sub-6GHz doesn't bring the generational speed increase that is often hyped by the cell industry, it also doesn't have the
ridiculous range limitations of mmWave, and it's more practical for actually building a cellular network that works.
The split between 5G standards has to do with what spectrum the world's various governments have made available. In the United States, 24GHz-90GHz mmWave is just what's available to use. While other governments have opened up slices of the sub-6GHz spectrum for auctions, the US has not and has no plans to. 5G is devolving into a standards battle, and it's the US versus the rest of the world.