Thanks for these suggested clean-up commands. Sadly, trying them was to no avail!
Only thing that is working was restarting my Docker container. Logically, I cannot keep on relying on that to reflect each change on my Laravel back-end.
I am using PhpStorm as my IDE, but even calling the back-end from PostMan has the same results. This leads me to believe it might be caching the code on Docker's side.