Given your hardware I’d say you’re platform is sound.
Have you removed the MMM-pages & MMM-page-indicator folders in the ~/MagicMirror/modules folder.
Do you have a backup of the original config.js file (~/MagicMirror/config/config.js)
Possible Test Solution:
If you had a copy of the original config.js file and did a backup or rename of your current config.js file you could just add the MMM-Carousel settings into the original or a vanilla config.js file and ‘pm2 restart MagicMirror’ to see if you get the same result.
As a way of testing its a quick way to test the module and/or MagicMirror.