I'm not sure if this has anything to do with the problem you're having but, according to the docs for require:

Note that the file will not be included twice under the same specified name.

Maybe do would be better than require for this? Or better yet, make proper exporting modules out of these files, and define functions print_content (for example) in these modules to perform the desired printing; then your code explicitly calls the appropriate one among these functions after executing the require statement.