yesterday was released new version 1.13.0 that solves the issue with deleted/shifted features. Please update the app and feel free to contact us if issue persist.
I hope I can understand it correctly. You edited some attributes when suddenly some features (objects) from the same layer disappear? I'm sorry I'm not sure what you mean by "tile".
that's really strange and it shouldn't happen. Anyway, please send me the project and I'll check it. Please open Menu > Projects > options of the project > Export Project. App create the .zip file with the project data. Please send me this .zip file . (you can create a new private ticket if needed)