Cities XXL Maps- lost resources and connections

No resources or road/highway connections for certain maps.
Specifically the "Hong Kong" and "Smoke on the Water maps".
Three other maps, game defaults and custom mod maps, all work fine.
Maps in question are empty maps, only some light terraforming performed.
Even loading the "start over" option does not restore the missing features.

 

Restarting the game did not restore resources, neither did deleting the city and start again with the same map.
Luckily I had not invested much time in the cities.
I checked about 10 more default game maps and most were without resources and connections.
After the 3rd clean game reinstall, all the maps successfully restored all of their features. I would still like to know what was going on though, hopefully to avoid such issues in the future. Much rather be building than trying to analyze and solve problems.