I just collected four strawberries...and received four hot peppers!
i'm having the same problem! I plant strawberries, when I collect it says strawberries (lower right on screen) but I also get a popup that I can't hold more Hot Peppers (upper right on screen).
~~~~~~ Dragon Story, Castle Story: Nuicakes Playing on an iPad Pro 11" with4 GB RAM, 512 GB storage, A10X Fusion cpu and using 5 GHz wifi.