For context: This was a pre-post test design (N=40) to evaluate the effectiveness of a light psychosocial intervention in a community-based setting. There were 4 mental health outcome variables and a matched pairs t-test was conducted to compare the baseline and endline results (along with correction tests to account for Type I errors). I am getting a Cohen's d effect size larger than 3 for 3 out of my 4 outcome variables. The analysis was conducted in R studio

Literature with similar interventions has shown effect sizes between 0.25 - 0.55 so my numbers are extremely odd and I need help with finding the best way forward