Hey Petr. At first, I cleared the Feedly cache, remove the app and reinstalled it. Trouble came back. Redid the same thing by removing app data and cache before uninstalling / reinstalling. Same trouble. Redid exactly what you asked (cleared data + cache, uninstalled, rebooted, reinstalled) and so far so good!!! I did have a problem though. After installing Feedly, Chrome would not start. Had to reboot once again.