1, Can't login after change password for "admin@localhost"
Invalid username or password
Error: Invalid username or password
at SessionModel.<anonymous> (/home/joplin/packages/server/src/models/SessionModel.ts:28:20)
at Generator.next (<anonymous>)
at fulfilled (/home/joplin/packages/server/dist/models/SessionModel.js:5:58)
2, In App Check synchronization configuration after setup Joplin Server as sync target, it can't use created username and password.
Error. Please check that URL, username, password, etc. are correct and that the sync target is accessible. The reported error was:
3, I use 10.0.1.251 as RPi IP address, add 22300 and /joplin to different config file, I am very confused. Better use uniform config for all of them.
In Joplin App, Joplin Server URL: http://10.0.1.251:22300/joplin
In docker-compose.yml,
For the APP_BASE_URL, you should use whatever the address will be through the proxy. So in your case that would be http://your-nginx-webserver/joplin.
Regarding the login, what storage backend are you using? Are you using the PostgreSQL backend? I haven't used the SQLite backend so can't give feedback on that. I haven't encountered any issues with the Postgres one. I use a second user I created for my Joplin syncs.