Fix Mobile Coupon Bug

I’m running a WordPress site that uses Fluent Forms for user registration. The built-in coupon code field works flawlessly on desktop, yet the very same code fails to apply on any mobile browser I’ve tested (iOS, Android, Chrome, Safari, even incognito).

I haven’t introduced any recent changes to the mobile version and I’m not running mobile-specific scripts or plugins. Because I’m unsure where the settings might diverge between desktop and mobile, I need someone to:

• pinpoint the exact cause of the coupon code failure on mobile
• implement a clean fix in Fluent Forms or related theme/plugin code
• confirm the solution works across common mobile browsers and devices without breaking desktop behavior

This is a focused troubleshooting task—no redesign or feature build required—just a reliable, tested fix so users can apply coupon codes from their phones. Let me know your approach and how soon you can deliver.