Unstable reCapture implementation - stop spam registrations

Experience Level: Entry
We are looking for an experienced WordPress developer to help us resolve ongoing spam registration and login issues on our website.

The Problem
• Our site (running the Homey theme) is receiving a high volume of fake email registrations.
• We attempted to use Google reCAPTCHA via the theme’s built-in option.
• reCAPTCHA v3: Not compatible with the theme.
• reCAPTCHA v2 (Checkbox “I’m not a robot”): Works initially, but soon stops loading for most users, giving the error:
“reCAPTCHA failed: the response parameter is missing.”
• When reCAPTCHA is disabled, the site is flooded with spam accounts.

What We Need
• Diagnose and fix the issue with reCAPTCHA not loading.
• Implement a reliable anti-spam solution (reCAPTCHA v2, v3, or alternative).
• Ensure real users can log in and register smoothly, while blocking spam bots.
• Recommend and set up any additional security measures if required.

Requirements
• Strong experience with WordPress, reCAPTCHA, and spam protection.
• Familiarity with the Homey theme is a plus.
• Ability to troubleshoot theme/plugin conflicts.
• Clear communication and timely delivery.

Deliverables
• Stable reCAPTCHA (or equivalent) implementation that works consistently.
• No spam registrations while allowing genuine users access.
• Brief documentation of what was changed/fixed.