do displacement maps only work on flat surfaces?

Only thing i was able to do to fix this was to just turn off tessellation for this material, but i think it would look better if it had more than just a little normal map on it. Basically, my question is: is there a way to use tessellation/disp map without the material exploding out from the object?

(if the image doesn’t work later, here’s a reddit post to figuring out why it was exploding like that – https://www.reddit.com/r/unrealengine/comments/azdzns/it_looked_okay_yesterday_i_dont_know_what/)

that’s because a mesh has hard edges, different materials, or uv islands in those spots.
When a game engine renders a mesh it has to split the vertices at those points. So anywhere the mesh is split for rendering the displacement map will cause cracking.
I can see that mesh has some hard edges.

It can definitely be for cylindrical objects like the one you are showing here, I did a windy log with displaced bark once. Just be sure to have few UV seams as possible–makes things easier for painting-- and make sure there are no texture seams where the UV seams are, otherwise it is prone to cracking.