What does 0/3, 1/3, 1/4, 1/11, etc. mean in the context of assigned reviews in a journal management system?
My intuitive guess is that it's the number of reviewers who have completed their reviews / been invited to review. The journal invited 3 reviewers in the first month. Two months later, one reviewer finished the review, but the other two either didn't accept the invitation (more likely) or didn't submit a review. The journal's policy is to have at least two reviews per paper, so they invited more reviewers, to the current count of 11.

If this guess is correct, then there's nothing to do except wait. You can also write to the publisher asking what the number means - it can cause no harm.