Not sure if you have solved but I had same issue, what you need to do is create a liability account for your agent. Then create a payment in tenant manager and it will ask you to select which invoice the payment is to come from. So for example say you received £450 in October and you incurred a £55 expense you would allocate the payment as being made from the tenant on your behalf as its coming out of the rental income.
This way it will only show you received £395 in landlord vision, see link below although I did not use misposting I just created an account for the agents expenses as a liability it works same way...
https://landlordvision.userecho.com/kno ... f-landlord