The Kindle Fire 7 was first released in September of 2015, so it is now over 4 years old. Amazon typically supports their devices for around 5 years, so the Kindle Fire 7 is likely approaching the end of its supported life. That being said, Amazon has not officially announced that they are no longer supporting the device, so it is still technically supported at this time.
If you are still using the Kindle Fire 7 and are having issues, you can try contacting Amazon customer service for help. You can also check out the Amazon Kindle Fire 7 Help Forum to see if other users are experiencing the same issue and find a potential solution.