I have Maven multi-module project with such structure:
parent-pom-project
-- module1
-- module2
At the paren
Although old I had the same problem and didn't find the solution here. For me the problem was Eclipse which I use parallel to mvn on the command line. Eclipse instantly called process-resources after I did so on the command line.
Thus the solution was to select the profile in Eclipse (Project->Maven->Select Maven Profiles).