As you can see in the images, the processors I choose are not active.
L2A, which remains selected even if I don’t select any of them, does not appear after saving.
If I hit the save button without selecting any of them:
I will try to reconstruct your issue from the first two images on my system. Have you checked the sen2agri.services logs when you click save? Maybe there is an error message.
Concerning the last picture… If I am right, L2A is never listed as processor when active, but working well. Don’t know why the developers did not listed it. But the service works (check sen2agri-demmaccs logs)