This usually is the case with a form design where there are multiple fields, images and detailed text is added to the form.
To fix this issue you need to have a mobile friendly version of this form available which is compact in design.
Display device for each form can be selected in the Behavior step. So you can have a detailed version for desktop devices and a compact one for mobile devices.
Duplicate your existing form. Select only desktop devices for the original form in the Behavior step.
Make appropriate changes for the mobile version by adjusting image size, having less fields added to the form or changing the text of the form to make it more compact in nature.
You can rename different versions of your forms for your reference as well.