Artifacts and white pixels when working in the h265 10bit codec

These apps all do things very differently from one another, including how they use system resources for ... what. Resolve specifically is oft set to create "optimized" media, similar to proxies, automatically. And does so in the background. Which is useful at times, not so much at others. All things having trade-offs.

And those differences defiinitely include how they work with this nasty long-GOP stuff. Which is the hardest media for an NLE ... period. For example, computers that can play three streams of 8k RED can still struggle with H.265 422 10-bit. Which is why most colorists I know immediately trancode such media before loading in to get ready to grade a project.

So details on your hardware here would be of use. The OS, CPU/RAM/GPU, GPU driver, and the type of disc the media is on. How many discs are you using, that sort of thing.

Do you mean that the PC cannot handle the h265 codec? But in davinci resolve, everything is displayed correctly and without delay. I don't know how to work in DR, but I installed it to check.

Fujifilm x-t3. 

What camera created that media?

And in general, while long-GOP media is fast to write to card in the camera due to the specialized chips to do just that in the camera ... and useful as a delivery format  ... the compression type is nasty in an NLE.

I assume you are aware that computer needs to get, decode & decompress up to 30 frames to show the next one, right? That's a load, on top of grabbing bits of clips pasting them together, throwing on audio and video effects  ...

• This is what I do, but without decoding the editing process is very slow.​

Turn off decoding.