Running a 2-week test on why students drop before the end

I run a six-week group programme for photographers moving out of freelancing. Four of my last nine finished. I keep hearing 'life got busy,' which tells me nothing. For the next round I'm putting every check-in in a shared WhatsApp thread and posting the weekly task the same day each week, so the quiet people are visible instead of invisible. I don't think the content is the problem, but I'd rather find out than keep guessing.