With possible alt+tabbing in game I assume you play with launcher, have you tried playing without launcher?
\game\client\eso64.exe or \game\client\eso.exe
Then ctrl+alt+delete to start Task Manager and open browser...
ZOS_DaryaK wrote: »Please submit support tickets at https://help.elderscrollsonline.com/app, be sure to include your game consultant report so our support agents can troubleshoot effectively.
Than it's weird, that you can use Alt+TAB when you start game from no-launcher shortcut.
I never use the launcher other than to update after a patch.