Just to drop a newer keeper's 2 cents in here. The advice I got from several people here as well as the breeder where I purchased my guy from, was to keep him on what the breeder was feeding until he was eating very consistently for me. So my guy came to me eating one live rat fuzzy a week, and I'm on feeding 6 now with no issues. So maybe when you starting trying to transition it was too soon? I'm not sure, I wish you the best of luck though, I know the two big things I was worried about when my guy arrived was eating and shedding properly.
To be honest, I don't know that I'm going to swap to F/T, I think as long as you're keeping your animal safe while feeding that F/T Vs. live is just a preference. Personally I have a family owned reptile store close to me that breeds their own feeders, so I can actually go into their breeding rooms and confirm that their rats and mice are being housed and treated humanly and are well fed and happy, so it doesn't bother me to pick one up every week.