You need to talk with your clients to see how involved they are with the rentals. There is a safe harbor for rentals that qualifies them for the QBI. See link for more info.
https://www.irs.gov/newsroom/irs-finalizes-safe-harbor-to-allow-rental-real-estate-to-qualify-as-a-b....
Also see this from Intuit.
https://proconnect.intuit.com/support/en-us/help-article/federal-taxes/understanding-qbi-rental-real....
