The "Invalid Google 2FA Code" error shows up whenever the code from the Google authenticator app does not match or is incorrect. There are several reasons why this might happen:

• Incorrect code: You may have mistyped the code or entered the wrong digits. Double-check the code you're entering and make sure they match.
• Code Expiration: Google 2FA codes are typically time-sensitive and are usually valid for 30 seconds. The code may expire if you take too long to enter it, causing the system to reject it. Wait for the new code and enter it promptly.
• Incorrect time settings: Google 2FA relies on the correct time and date settings on your mobile device and the server. If there's a time discrepancy between the two, the generated codes might not match. Time zone differences could cause this problem, especially if you travel. The code will likely return the error if the time on your device does not match the time on Google's servers. Change your device time to automatic and sync your Google Authenticator app.
• Device change: If you've recently switched to a new mobile device and set up Google 2FA on it, the old codes generated on the previous device will likely no longer work. Use the codes from your new mobile phone.