Do you have a .babelrc file in your project? I was having import issues when I upgraded a project from v1.4.3.2 to v1.4.4.1.
Sometimes cleaning and building your project from scratch can fix the issue or help you determine what package is causing you issues. You should delete your node_modules by rm -rf node_modules, clear meteor by meteor reset, and then run meteor npm install before running your project again.
If you have been using git and committing your .meteor files you can roll back to before your latest update.