Operating system
Android
Joplin version
3.6.21
Sync target
Dropbox
What issue do you have?
After reinstalling the app on android, I cannot see my notes any more
After reinstalling the android app, did you set up sync to your dropbox sync target again? What happens when you manually sync? Any error message?
Do you have a JEX export backup of your notes somewhere for safety?
This guide might help: How to fix synchronisation issues and start over