I had some issues with my aluminum roof. Had leaks around antenna and a seam in the rear corner.
I removed antenna and scrapped off all the old putty tape with a plastic scrapper and bought good quality butyl tape and reinstalled the antenna with that.
Also check around your vent windows and fridge and plumbing vents.
Any sealer that is cracked or loose around the edges should be removed and resealed.
I like Dicor Self leveling sealer for the roof.
Make sure you clean the roof well before applying sealer or tape, you want a clean surface for a good bond.