The Author Payroll extension works but it is a bit hard to setup and use. The Tip the Author extension works fine for many people. I can’t think of anything else right now, but it should be something trivial.

• You could try disabling all other plugins (besides wallets and tip the author) and see if the problem persists. You could also try with a different theme. If you discover an incompatibility, let me know, and I’ll see what I can do to fix it.
• If you like I can login to your test page and have a look at what the problem might be.
• Finally, there is a small chance that there might be an error that would show up in your WordPress logs. Instructions for enabling logging are here: https://codex.wordpress.org/Debugging_in_WordPress

Let me know.

kind regards