Can I confirm that you are following the correct procedure for takeoffs to be logged, i.e. requesting ATC clearance before taking off?
There has been a long standing “issue” with takeoffs not being recorded in MSFS unless this procedure is followed. More information in this thread:
https://forums.flightsimulator.com/t/what-are-the-requirements-of-the-sim-to-log-a-take-off-and-a-landing/467447.