Using the seed 4 and otherwise default settings gives the same map as using the the 5 and otherwise default settings. Only the tree graphics seem to be of different variations, the positions are the same.
Using 4:
Using 5:
I'm an admin over at https://wiki.factorio.com. Feel free to contact me if there's anything wrong (or right) with it.
Thanks for the report however this is working correctly. The seed seeds the deterministic random generator and some seeds result in the same (or very close to the same) internal RNG state resulting in what you see.
You'll need to give it larger/varied numbers.
If you want to get ahold of me I'm almost always on Discord.