Alright. Please specify the map formats you played, and the difference between them in regards to what you see with the growth bonus from dwellings.
Heroes 1 maps (former RoE) are marked with the red square with a big H letter.
Heroes 2 maps (former AB) are marked with the familiar Ironfist family crest (lion shield).
Heroes 3 maps (former SoD) are marked with Sandro's face.
H3SW maps (former WoG) are marked with MMVI red dragon face.
If some of the maps were generated by RMG, this is also a valuable information.
Note however, that all your savegames will be marked as H3SW maps. This is a bug-feature of ERA platform. You can just specify the map name so I will know exactly which map has the problem.
P.S. In fact, to this day we managed to fix this bug to 95% of cases, but some things still need to be done for v0.8.1 update.