I suggest you have a read at the Documentation for the extension. Settings do not come under the “modern-fortran” tag.
As I mentioned above, the functionality is there, it is tested and does work. I should know given I wrote all of these programs, so please read the docs and adjust your setup accordingly.
Modern Fortran WILL NOT WORK with any of the other 3 extensions you had installed alongside and it will fail quite visibly throwing pop up errors asking you to disable/uninstall the other extensions. I think that is a pretty clear indicator as to why it hasn’t been working.