Hi! I see you're stuck in an authentication loop on Messenger Kids, where the login screen keeps coming back without letting you pass through. That can be tricky, but let's work through some steps together to get this sorted out.

To start, could you confirm:
- Are you logging in using a parent's Facebook account to authorize Messenger Kids?
- Is the same device being used to log in both the parent and the kid's account?
- Have you recently tried any steps like reinstalling the app or clearing cache?

Meanwhile, here’s a clear step-by-step plan to try:

1. Log into the Parent’s Facebook First on the Device: On the Windows device you're using, open a browser, go to Facebook.com, and log into the parent’s Facebook account linked to Messenger Kids. Sometimes, that connection is necessary before the kid’s login proceeds.

2. Approve Login From Another Device: When you attempt the login on Messenger Kids, it may request parental approval. Try to approve this request from another device (like a phone or another computer logged in as the parent). This can break the loop.

3. Uncheck and Recheck the Kid’s Name During Account Selection: If prompted to select the kid's account during login, try unchecking and then rechecking the name. This has reportedly resolved the loop for some users.

4. Clear Browser or App Cache: Since you're on Windows using WebKit, clear the browser cache and cookies associated with Messenger Kids to remove any corrupted session data.

5. Restart the Device: A simple restart can sometimes refresh authentication tokens and clear temporary glitches.

If after trying these you still face the issue:
- Let me know if you see any specific error messages.
- We can explore clearing app data or checking for account authorization problems in more advanced settings.

Would you like me to guide you through any of these steps in more detail?
Are you satisfied with the solution I provided so far?