Chat box not working on phone

I'm hoping someone can help me. I have a member using her Samsung galaxy one phone to access the chat box on my forum. She can log in but can't type anything or hit send button. 
It's like her phone doesn't recognize them. 
I've turned it off and back on. I've switched it to a pop up window in hopes that would help but still doesn't. 
Any ideas? 

Thank you.