There are times where you have a problem synchronizing your mail with your Android device. To get rid of the Yahoo mail syncing issue on your Android mobile, proceed with the steps given below to fix the issue of Yahoo mail not syncing on Android.
The first step is to check whether you have updated your Yahoo app. if you are not updated with the latest version of Yahoo mail, you need to update it.
Sign out from the Yahoo mail and sign in again.
Try enabling SSL for your Yahoo account. To do so, tap the cogwheel icon at the top and then select Mail Options.
Go to the General tab and then select the Turn on SSL option.
Now, tap OK and then Save.
If the issue persists, turn off your account in the Yahoo app.
To do so, select the account that is accessible in the app by turning them on or off.
Tap the Sidebar icon
Choose Manage Accounts and slide the button off
Now, uninstall and reinstall the app and check if the issue Yahoo mail not syncing on Android is resolved.