Drosophila is a model. Let’s say you work in a lab studying photoreceptor chemicals (opsins). You won’t then be able to jump to a lab studying acoustic communication just because drosophila is the organism they’re working with. Working with fruit flies is literally like working with lab mice or rhesus monkeys. It’s just a cheaper, easier tool to use because its genome is so small and they replicate so quickly.
You need to do as @blossom has suggested, figure out the problem(s) that you want to spend your career tackling and pick the lab most aligned to that goal.
Edit: I cross posted with @ColdWombat. Follow their advice. The great news is that it’s the lab you prefer anyway.