Why Am I Gaining Weight Despite Eating In A Calorie Deficit, Exercising Regularly?

Hello. I am a 46 year old male trying to lose weight. I weight 275.....well, now i m 280. I have started the calorie deficit plan. I eat 1 egg with 2 whole grain toast, no soda.....just coffee in mornings, almond milk, water and flavored waters. Lunch is spinach with mixed greens and grilled chicken or a sandwich. Dinner is usually salmon with veggies or something similar but almost always something fishy. I don t smoke or drink alcohol. I play pickleball for 4 hours each weekend and for 3 days during the week i ride on my Nordictrack S22i which i love. My base caloric needs is around 2300 per day so i keep my calories intake around 1800 each day. When i bike ride i average burning between 300-500 calories and i m not sure about how much i burn while playing pickleball, but i assume it s a lot since it s so intense, especially since i play in south florida heat. I do everything right but my weight keeps steadily climbing. Whats wrong? I m perfectly healthy....just a little high on my blood pressure due to the weight i m carrying around.