"The simulator version is higher than the version Flow has been tested on. This might break some features or Flow entirely."
This message may appear if you have opted for beta builds or if there is an official update for the simulator that the team has not yet tested with Flow.
Normally, general simulator updates should not affect any features. However, this message serves as a precautionary statement while you wait for an official update that supports the current PRODUCTION release of MSFS 2020. If you notice any unusual behavior from Flow, this mismatch is likely the reason, and all you need to do is be patient.