PhpStorm testing: Can't select PHPUnit to run test

I cannot run the directory / folder as a PHPUnit test from the context menu - it offers debug and browser launch only as a php script. I can set up one of the tests in the Edit Configurations panel and they work fine, but I have hundreds of test files and I cannot install them individually.

At some point in a previous project, I could Ctrl + Tand it would run the file / test I was in as a PHPUnit test, without any previous configuration for the file. I went through my setup and they look the same.

The "Settings -> PHPUnit" script is set to vendor\autoload

, the default config file is pointed to local phpunit.xml

.

"Edit Configs -> Default -> PHPUnit" is set to use the default config file.

Again, I can run PHPUnit tests, it seems to me that my PhpStorm no longer recognizes the files as suitable for PHPUnit unless I list them each.

PhpStorm 2017.1.3
PHPUnit 5.7.20
PHP 5.6

Any advice would be appreciated, thanks.