RTV disabling fields in pop-up maker modal

With RTV turned on, all fields in a form shown in a pop-up maker overlay are disabled.

Without RTV, the HTML looks like this:
<div class="ginput_container ginput_container_text"><input name="input_1" id="input_2_1" type="text" value="" class="medium" tabindex="0" placeholder="Name *" aria-required="true" aria-invalid="false"></div>

With RTV, it looks like this:
<div class="ginput_container ginput_container_text"><input name="input_1" id="input_2_1" type="text" value="" class="medium" tabindex="0" placeholder="Name *" aria-required="true" aria-invalid="false" disabled=""></div>

The ‘disabled’ parameter has been added at the end. Setting it to false makes no difference, but removing it means the form works as expected.

This looks to be the same issue as https://www.ads-software.com/support/topic/rtv-breaks-overlay-version-of-form?replies=3

Can you help?

https://www.ads-software.com/plugins/real-time-validation-for-gravity-forms/