Reproduction steps:
Step 1.) Complete exploring 2 or more exploration sides on the Asteroid Belt cmap
Step 2.) Defeat the opposing armies of all exploration sides except the last exploration side
Step 3.) Launch a new exploration on the exploration sides
Step 4.) Defeat the opposing armies of the last exploration side manually and the second wave automatically
Step 5.) After pressing OK of the battle results you'll be slung to the active Venus province on the cmap