I’m not able to respond to requests for copies of my papers at present. I receive an email and when I press the button i go to the App but nothing more. Has a glitch in your system been reported?
Go to https://www.researchgate.net/requests to find the requests to your papers. At that place you will be able to reply. - You are not the first one who reports about this problem here. Hower, you wrote to the ResearchGate community, not to the team. It would be good to inform the support team - see the "Contact us" button at the end of each page.