Image upload field on form still being required

Hi,

I have a template that uses an image upload field.

We're having an issue when trying to submit the form that says you still need to select an image, even though this field is not required (required="false"). Do you have any idea what might be causing this? We've noticed it on mobile and Chrome, but Safari still sends okay. The template part for the form with the image upload is as follows (everything else works fine):

<div class="col-xs-6 col-sm-6 col-md-4">
            <label>Optional image upload of problem area:<sup>*</sup></label>
            <perch:input type="image" id="imageupload" class="imageinputfile" required="false" label="Upload image of problem area" data-multiple-caption="{count} files selected" multiple />
            <label class="uploadimagelabel" for="form2_imageupload"><span>Select an image</span><i class="fa fa-upload" aria-hidden="true"></i></label>
            <small>*Will be used in strictest confidence</small>
        </div>

The extra classes here are for styling it into a more aesthetic button. I tried stripping all this out but still have the same problem.

Diagnostic:

Perch Runway: 2.8.34, PHP: 5.4.45, MySQL: 5.5.46, with MySQLi
Server OS: Linux, cgi-fcgi
Installed apps: content (2.8.34), assets (2.8.34), categories (2.8.34), perch_blog (5.0), perch_forms (1.8.3)
App runtimes: <?php $apps_list = array( 'content', 'categories', 'perch_blog', 'perch_forms', );
PERCH_LOGINPATH: /perch
PERCH_PATH: /home/fullfatwebsite/public_html/zenithcosmetic/perch
PERCH_CORE: /home/fullfatwebsite/public_html/zenithcosmetic/perch/core
PERCH_RESFILEPATH: /home/fullfatwebsite/public_html/zenithcosmetic/perch/resources
Image manipulation: GD
PHP limits: Max upload 25M, Max POST 128M, Memory: 256M, Total max file upload: 25M
F1: 6a33f95eca3667f9e0c39bf5ca2980fe
Resource folder writeable: Yes
DOCUMENT_ROOT: /home/fullfatwebsite/public_html/zenithcosmetic
HTTP_HOST: zenithcosmetic.fullfatwebsitedesign.co.uk
REQUEST_URI: /perch/core/settings/diagnostics/
SCRIPT_NAME: /perch/core/settings/diagnostics/index.php