Can’t lose weight

I’ve been using MyFitnessPal truthfully for 6 months now. I’m 205lbs and have averaged 2100 calories a day and 1h 9m a day exercise for the entire time. I did lose a bit to start with but nothing for 5 months.

I used to drink a lot more alcohol before I started this, now it’s normally just once a week.

Exercise has been weights and a lot of running and cycling (10 mile runs / 100 mile rides, I cycled for years). I’m the fittest I’ve ever been by far, resting HR is high 40’s.

Any ideas? It’s not all muscle or anything as I’m still quite a big unit.