SOLVED!

The avenue I was wandering down was the "it has to be a VSCode issue..." HOWEVER, upon doing a task in laravae for a client, I noticed that the problem tab WAS reporting code syntax errors... SO I then shifted my focus to "It has to be a problem with the .jar file..."

Long story short - turns out that the JRE was not installed on my version of macOS (Sequoia 15.4.1 )... Unfortunately homebrew doesnt seem to allow the download, so you have to download and install the JRE directly from the java website (making sure you install the ARM version of it if you are on a M3 Mac).

NOTE: you can test if this is the reason CFLInt doesnt work for you by hitting terminal and running the command: java -version