Take a look here for the best recommend aps with real debrid setup.
Make sure your real debrid is up-to-date.
Re authorize your account on the app/apk you are using
Delete your devices in real-debrids website and re add them
Make sure they are added in real debrid.
These steps are a must and will solve the issue 9 out of 10 times. Also check real debrids Twitter for status updates.