It seems that this mod is moving the Shimmer Biome to generate closer to the worlds edge than normal. This means that mods that add biomes or structures near the oceans such as Homeward Journey's Abyss will cause the Shimmer to be deleted.

This might also effects calamity, but I can't say due to not playing it. But after generating over 10 different worlds with his and Homeward Journey active it deleted the Shimmer every time.

If possible moving the Shimmer to the other side of the map from the catacombs. Or to below it should fix the issue. If that is possible to specify I mean.

I have posted this on both Spooky and Homeward Journey just in case. Since it is only with both of the mods together that causes this to happen.