There are several files open with gedit.
Is there a keyboard shortcut to go from one tab to another tab?
Ctrl + Alt + PgUp goes to the previous tab. Ctrl + Alt + PgDn goes to the next tab.
If this does not work, see the Documents menu.
You can try this "Go to the nth tab Alt + n ". This works great for me.
Ctrl + Shift + Tab should switch between tabs.