It seems to be a problem with the browser cache. so you should reset the browser history, cookies and cache data. after that, you should try to reload the yahoo mail account. it should start working fine on your device. To clear the browser cache on google chrome, you may follow the instructions given below.
1. open the google chrome browser.
2. Go to the chrome://history
3. Click on the Delete browsing data.
4. Here, you need to select all browsing data.
5. Press clear browsing data.
Once you will delete all data from the browser, you may now retry to login your account. it will start working fine on your browser.