Thank you for contacting Presonus Technical Support. Sorry to hear about the recent issues you have been experiencing.
That is strange, effects should work on all songs.
Reset your Studio One settings and test again:
Go to Help>Open Settings folder.
Copy the contents of the folder over to a folder on your desktop.
Close S1 and delete the contents of the settings folder with the exception of the user.license file as well as the "Extensions" folder.
Open S1 and go to Studio One>Options (Preferences on a Mac) to reconfigure your settings.
Test to see if the problem is resolved. If it is not, please feel free to copy your settings files back over from the backup that you created in step 2.
*If you are missing presets or Sound Sets after doing this, simply double-click one of your Sound Sets under Documents>Studio One>Sound Sets.
If the issue remains, please create a ticket to technical support, for deeper investigation.
Here is a link to create a ticket: http://support.presonus.com/hc/en-us/requests/new