With the latest update of MacOS Catalina (10.15.x), it seems that the keyboard shortcut to switch between Finder window tabs is no longer supported / missing!
This really annoyed me ’cause I use this every. single. day! The shortcuts are Shift + ⌘ + → (right arrow) OR Shift + ⌘ + ← (left arrow).
Here’s how to reinstate this [much needed] functionality. You’re going to add 2 custom keyboard shortcuts in…
System Preferences > Keyboard > Shortcuts
- Select “App Shortcuts” in the left side pane.
 - Click the [+] button to add a new shortcut.
 - In the popup:
- Application: choose “Finder.app”.
 - Menu Title: enter the exact name of each of the Menu Options (in this case, “Show Next Tab” and “Show Previous Tab”).
 - Keyboard Shortcut: literally, perform the shortcut on your keyboard that you want in the box.
 
 - Click “Add”.
 
Happy tabbing! …again.