Mark in your working site, the Catchpas have different IDs:
<img src="index_htm_files/captcha.php?0.368664474837497" id="captcha"><br>
<a href="#" onclick="CapRefresh ();" id="change-image">Not readable? Change text.</a><br><br>
<input class="contact-input" type="text" name="captcha" id="captcha-form" autocomplete="off"><br>
versus
<img src="index_htm_files/captcha.php?0.368664474837497" id="captcha-m"><br>
<a href="#contact_form" onclick="CapRefresh ();" id="change-image">Not readable? Change text.</a><br><br>
<input class="contact-input" type="text" name="captcha" id="captcha-form-m" autocomplete="off"><br>
One of the form's wrappers has an additional ID - id="Xxr_v6_contact_form"
Do note if you input in one and switch to the other, the input disappears.
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