I’d try to add a session or two of weights a week, or even a session of press-ups, dips, lunges at home. Build muscle which ups your calorie burn, and feels good too.
Ive recently done this by accident – new job sees me living in hotels a lot so,I’ve been pushing weights in hotel gyms instead of riding all the time. And I’m losing weight that I wasn’t losing riding. I think the long rides make me starving hungry!