hiya 
@2kpixy thanks for reaching out and welcome to the Netlify support forums! There may be a few reasons why this is happening:
- Network Issue: The issue might not be with Netlify but with the network of the mobile device of the person submitting the form. Some mobile devices might have network issues that prevent them from submitting the form.
- Rendering Issue: In this support guide, if your site uses server-side rendering or redirects that could interfere with form submissions, it might cause issues on some devices.
- Spam Filter: If a submission is flagged as spam, it will not appear in your form’s Verified submissions list but in the Spam submissions list. You can check this list to see if the missing submissions are there. More details can be found in our documentation.