Well first of all I don't think you need to be capturing and displaying the page body, it'll just show up in the replay log with extended log enabled, right?
I think the high level issue might be that you haven't had training and don't have a mentor/guide. Do you have these two things?
For the issue you're asking about, I would first ask which protocol you're using? I'm asking because if it's 'web http/html' then that is only going to capture server communication...And checkboxes/dropdowns only sometimes will trigger server communication, but not typically.
Please answer which protocol you're using and if you've had the proper training.