Jeez! Thanks to umair.ashfr answer here below, I finally hit the nail with an issue that was eating my neurons.
I had a password like DB_PASSWORD=ffjdh5#fgr on my .env, and MySQL connection was gracefully saying that "SQLSTATE[HY000] [1045] Access denied for user...", no matter what flavor of php artisan I was trying to run.
The problem was that "#" sign inside the password. BEWARE! That means the start of a comment, thus my password was silently truncated! The solution is to declare password like DB_PASSWORD="ffjdh5#fgr"
Regards