We also have an issue like this, this is what we have found:
There are some squares where we can't build roads, and in most of them, the resources there can't be harvested. When placing, the blueprint is marked blue, trying to place a road will cancel the blueprint but nothing happens.
Here's some of them:
-1988 W -1692 N
-2036 W -1660 N
-1963 W -1692 N