Clearing the cache on your phone can clear up many issues.
If you are using Internet browser that is stock with your Samsung phone, the controls are in a different place.
Instead of the TOP RIGHT it is the LOWER LEFT.
Lets clear your Browser Cache and see if your problem goes away.
Here are the screen shots to direct you.
|Then Select Settings|
Then Privacy and Security
Then Click on Delete browsing data
Then Select Cookies and Site Data then Delete
Wait for the data to clear then click the arrow in the Upper Left 2x.
This will bring you back to your browser so you can login again.