Android Firebase Addlistenerforsinglevalueevent Not Called

I have been working on an android app for the past few weeks or so, and I have been using firebase as my backend. I have had no trouble reading/writing from firebase, but recently,

Solution 1:

Same problem ocured here, but i'm testing with phone (huawei y560-l01).

Edit:

I solved the problem with uninstalling the application, unplunging the device, restarting the device, and than conecting and running the code again.

Solution 2:

I ended up resolving this by switching emulators. I'm not fully sure what the exact problem was, but that worked for me

Solution 3:

I found that the google play services version(can reference: google-play-services.en.uptodown.com/android/old) on the smartphone needs to match the firebase version declared in the dependencies. It will work not only on the emulator but also on the device(Samsung J7).