I was having the same problem & found that if I logged out and back in, all my recipes and batches came back.
I wish I had read this earlier! I made the mistake of removing the app and trying to reinstall it. (See this thread: https://www.brewersfriend.com/forum/threads/where-is-the-app.16087/) I can't find it in the store anymore, but it is still in my purchased list. I now have to open the app from my purchases.