Consider changing airports to Miami. There is UA1680 that leaves at 8:25pm which would give you 2 hours to clear.
While it may not be preferred for you it is an option & United should change You to those flights if you request due to the tight schedule change - eventhough they are still selling that connection to FLL.
Another option is to just risk the current connection & if you miss it go directly to the Miami gate & try to get on that flight. Just make sure to bring a appropriate carryon as you won't get your luggage until the next day.
Option 3 would be to get United to reroute you on UA9127 & UA8849 which are Lufthansa code shares directly into Miami via Frankfurt.
If you do nothing this would be a ideal trip for travel insurance to pick up the overnight hotel charge in EWR if that ends up happening.