It is expected behaviour that the F28 should be susceptible to floating when entering the ground effect. The F28 has a low wing, much lower than most conventional aircraft due to the lack of engines, and it also has a very thick wing that is designed to generate lots of lift at low altitudes. Combine both of those factors with an approach speed which is similar to more conventional airliners, and it's likely that the aircraft will be rather susceptible to ground effect.
If an approach is carried out following standard procedures, it is standard to extend the speedbrake as the aircraft crosses the runway threshold (there is a callout for this in the F28 Professional). When the speedbrake is deployed, the extra drag will slow the aircraft down to the VREF speed, thus reducing any tendency to float. Upon touchdown, the liftdumpers will automatically deploy (if armed), which are used to spoil any remaining lift that is being generated by the wings.
The act of extending the speedbrake during the final approach is something unique to some of the aircraft we develop (F28/146/RJ), and does differ from the more conventional aircraft, but once you start doing it a few times, it starts becoming second nature.
There are few settings in the simulator that we may recommend changing that could improve your experience with both points you raise:
We recommend using linear sensitivity curves for all of our aircraft. This is what the flight models in our aircraft were developed around, and provides consistent control throughout the control range. The sensitivity curve can be adjusted in MSFS 2024 Settings > Control > then click on the cog icon next to your joystick/yoke/controller > Hardware Settings.
We recommend using the "Low" turbulence setting. Based on various feedback we receive from real-world pilots on our testing teams, the "Medium" and "Realistic" turbulence settings tend to produce overly aggressive wind effects in the simulator. Therefore, reducing this setting to "Low" will provide a more realistic experience, and may reduce any wind effects/ground effect caused when low to the terrain. The turbulence setting can be found at MSFS 2024 Settings > Assistances > Turbulence.
Hope that helps.
Mark - Just Flight