I had a similar experience myself, on Portmore loch.Not done by myself but a colleague was fishing a deep pool behind me at night, casting upstream & stripping his flies back & felt 2 solid takes. After a few minutes of playing the fish, it was duly netted & both his point fly & dropper were extracted from a very greedy sea trout.
Wind was blowing a hoolie and it was very difficult to stay in any kind of contact with my flies, anyway finally got a take and when I got the fish in it had taken the damsel on the tail and also the bibio muddler on the top dropper.
Not sure what it didnt like about the middle dropper!!!