Seed and world generation (Minecraft)

Hello. Faced the problem of generating worlds when using the same Seed.
It all started when I went to a special site for tracking slime chunks to build a farm. I killed half a real day for excavation according to the guides, and then another whole night waiting for the spawn of slugs, but all in vain.
I used the site, entered the Grain of my world and found the chunks I needed. After failing with the found chunks, I found others, but at a distance from my location. Then I thought that it would be nice to test these points, but only with Creative mode, where it can be done faster and more efficiently. And then there was a problem. It's not really a problem, it just doesn't add up.
When creating a world, I enter the same Seed in the preliminary settings, I fly to the place where I am located in Survival AI .. and the worlds do not correspond to each other. And to be more precise, there are some inaccuracies. First, the biome. My home is in the High Hills biome, but the new world in the creative at the same X and Z coordinates shows that it is the Plains. But the coordinates are absolutely identical. Everything, completely and completely (except for indicator C). The landscape is different, the environment too. There are similarities, at least in the neighborhood. Because at the same distance from my biome is Taiga. In Survival, the Plain is also next door, but to the left of Taiga. Actually, the second part was "second". When test creating another world with the same Grain, the world is identical to the second attempt, but both are still not similar to the original.
That is, due to the inaccurate value of the Seed, I cannot track the slime chunks, but this is already a secondary issue. I would like to understand what is the reason and how can I create the same world as the original, if not in this way?
I can provide any media materials if needed.
Thanks in advance!