Why does my heightmap import badly?

First off, I am a total newbie to UE4 and game design in general, so I’m probably being insanely stupid. But I’ve tried looking at all of the tutorials, all of the documentation, and I just cannot figure this out. Here’s my problem:

I have used a program called terrain.party to grab a section of real life heightmap data from earth. The section is 60km in total. That is big I hear, but I also hear that it can be done. When I import my heightmap, having tried to follow more than a few recommended ways of doing so, it turns out like this:

It varies as well. Whenever I try to import my heightmap, it seems to condense it into a smaller piece, almost as if UE4 can’t hold that big of an area. It seems to shrink my heightmap. I know I’m messing up SOMEWHERE, but I haven’t really seen any awesome and comprehensive instructions, so if someone could please tell me how to properly import a heightmap into UE4 with all of the correct input information that I need to plug into everything, or show me where I can find this information out, I would be grateful.

Thank you!

I think it is a resolution error:
Your heightmap needs to have a 65399544*65399544 resolution for beeing at a size of 1:1 and it is impossible
In the photo you just need to go in landscape > manage > delete and then delete wrong component

Sorry for my bad english