Do you want to keep the existing notes from both accounts, either or none? i.e.:
None
Android only
Windows only
Both
Also be aware that changing sync targets when you already have notes can get a bit tricky and no process is without risks. Steps can be taken to minimise the risk, but risk remains.
Finally, I do not use OneDrive but I have read on this forum that some people have had issues with AndroidOneDriveWindows syncing. I do not know if that was a real problem , is still a problem, or was due to a specific system config of the users concerned.
still login automatically to acct2@gmail.com
-> any work-around's?
.
I wonder why there is NO place to enter the One Drive login credential directly in Joplin "Options" menu?
This is because Microsoft does not let you authorise Joplin to use OneDrive this way. When you set OneDrive as a connector you are shown (on first sync) a URL to click which takes you to a Microsoft login screen at login.live.com. You have to log into OneDrive / Microsoft with your username / password etc and get the Microsoft site to authorise Joplin for your account.
Joplin then gets a special token it then uses to sign in from then on.
The code from Microsoft is stored in your Joplin profile, so the fact that Joplin is apparently still logging onto the OneDrive account of acct2@gmail.com means either:
You have not renamed your profile as mentioned at step 2 above (did you see the Microsoft login screen again?)
You have previously used a hidden feature of Joplin to move your profile location
In Joplin Desktop go to Tools > Options > General. The very first line on the settings page starts, "Notes and settings are stored in:", what does it say after that?