Have found maps on multiple seeds which allowed us to search different places on the seeds we play on. Some are on sand, some are inland. No matter how we search, how deep, etc, e can not locate the treasure chest. One seed is a pre-1.14 conversion, however the others are not.
Thank you for your report!
We're tracking this issue in MCPE-82354, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated. In particular, please provide the world seed and the approximate coordinates where the treasure is supposed to be.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki