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See Editing form template

What content do you have in the form template?

Hi, thanks for the quick response.

This is our current template.

<div class="ic-u-container ic-u-container--narrow">
    [response]
        <div class="ic-c-grid ic-c-grid--twos">

            <div class="ic-c-form-group">

                <label class="ic-control-label">Your name *</label>
                <div class="ic-c-input-group">
                    [text* your-name class:ic-c-form-control]
                                    <span class="ic-c-input-group__addon">
                                        <svg class="ic-c-icon" xmlns="https://www.w3.org/2000/svg" viewBox="0 0 1408 1536"><title>icon-user</title><path d="M1600,1405q0,120-73,189.5T1333,1664H459q-121,0-194-69.5T192,1405q0-53,3.5-103.5a1017.5,1017.5,0,0,1,14-109A846.89,846.89,0,0,1,236,1084a514.45,514.45,0,0,1,43-97.5q27-47.5,62-81T426.5,852Q477,832,538,832q9,0,42,21.5t74.5,48q41.5,26.5,108,48T896,971q67,0,133.5-21.5t108-48q41.51-26.5,74.5-48t42-21.5q61,0,111.5,20t85.5,53.5q35,33.5,62,81a514.45,514.45,0,0,1,43,97.5,846.89,846.89,0,0,1,26.5,108.5,1017.5,1017.5,0,0,1,14,109Q1600,1352,1600,1405ZM1280,512q0,159-112.5,271.5T896,896q-159,0-271.5-112.5T512,512q0-159,112.5-271.5T896,128q159,0,271.5,112.5T1280,512Z" transform="translate(-192 -128)"/></svg>
                                    </span>
                </div>
            </div>
            <div class="ic-c-form-group">
                <label class="ic-control-label">Your email *</label>
                <div class="ic-c-input-group">
                    [email* your-email class:ic-c-form-control]
                                    <span class="ic-c-input-group__addon">
                                        <svg class="ic-c-icon" xmlns="https://www.w3.org/2000/svg" viewBox="0 0 1792 1408"><title>icon-envelope</title><path d="M1792,710v794q0,66-47,113t-113,47H160q-66,0-113-47T0,1504V710a530,530,0,0,0,101,87q362,246,497,345,57,42,92.5,65.5t94.5,48Q844,1280,895,1280h2q51,0,110-24.5t94.5-48Q1137,1184,1194,1142q170-123,498-345Q1749,758,1792,710Zm0-294q0,79-49,151a475.45,475.45,0,0,1-122,123q-376,261-468,325-10,7-42.5,30.5t-54,38q-21.49,14.51-52,32.5T947,1143q-27,9-50,9h-2q-23,0-50-9t-57.5-27q-30.5-18-52-32.5t-54-38Q649,1022,639,1015q-91-64-262-182.5T172,690Q110,648,55,574.5T0,438q0-78,41.5-130T160,256H1632q65,0,112.5,47T1792,416Z" transform="translate(0 -256)"/></svg>
                                    </span>
                </div>
            </div>
        </div>
            
            <div class="ic-c-form-group ic-u-gap-top">
                <label class="ic-control-label">Your message *</label>
                [textarea* your-message class:ic-c-form-control]
            </div>

            <div class="ic-c-form-group ic-u-gap-top">
                [submit class:ic-c-btn class:ic-c-btn--secondary class:ic-c-btn--block class:ic-c-btn--rounded "Send"]
            </div>
</div>

What other plugins and theme do you use on the site?

We use custom theme and these plugins:
Accelerated Mobile Pages
Advanced Custom Fields PRO
Async JavaScript
Contact Form 7
Cookie Notice
Google XML Sitemaps
WP Engine Advanced Cache Options
WP Fastest Cache

However, theme was not changed in a while and we tried disabling all plugins.
So it is not likely that issue is caused by theme or plugins, that is when we decided to report it here.

Hopefully this information helps.

Try switching to the default theme and deactivating all other plugins.

Why you are advised to deactivate plugins and switch to the default theme.

Don’t forget to delete all page cache.

If the theme and other plugins issue is really not the case, the only remaining possibility is that what you are using is not Contact Form 7.