this is the only thing i found for your phone. https://forum.xda-developers.com/t/debloat-workarounds.4189599/ please read as much as you can...
what is your model number? where did you get the firmware? do you have a link for it? what happened to your phone? how long has it been like this?...
and just to be sure what is your model number for the phone......like @Hadron suggested xda does not seem to have a forum for the A21.
here read this: https://androidforums.com/threads/general-rooting-discussion-please-read-before-posting.898388/ the info there is a bit old, but...
what did you do to get android studio to recognize your phone? it might help others who have your issue.
sorry i'm not quite sure i understand why you can't go into att and get a new sim card.....sounds like that might fix your issue.
wipe cache and data for the app and/or uninstall and then re-install the app.
what are you trying to do? there is no system in settings. you can find the systems apps within settings......but you will not find "system".
settings>apps>messages>storage>clear cache that's how it is on my note 10+ 5G. it maybe slightly different on yours.
yes https://support.google.com/android/answer/2819582?hl=en
just wipe cache for your message app....should fix the notification sound.
this site claims to have the firmware you are looking for: http://gofirmware.com/post/rca-11-maven-pro-rct6213w87dk can't verify that it is it...
ahhhh for android try this: https://www.lifewire.com/how-to-use-rar-file-extractor-android-4177752
put the phone in safe mode and see if it still happens. safe mode prevents any 3rd party apps from running. if it still does then you have an...
is free too much? https://play.google.com/store/apps/collection/cluster?clp=ggEFCgNtcDM%3D:S:ANO1ljLprFg&gsr=CgiCAQUKA21wMw%3D%3D:S:ANO1ljJaYYA
i believe rar is a compressed file so you will need to extract the file....
ummmm.....i see no smile in that icon....LOL no idea. you can just look into the phone's notofiocation.....but somethingtells me that the phone...
test app? what do you mean?
well.....my suggestion in my previous post is still what i would recommend.
is there a question in that post?
next time make a nandroid backup when you can. this way you do not have flash a firmware update. if something goes wrong you can nandroid restore...
As far as it appearing in hangouts....... Not sure. Maybe try wiping cache and data for hangouts. Or try uninstalling and re-installing hangouts.
can you download the image. i have not used hangouts in so long....didn't know people still used it....LOL
maybe try these: https://famisafe.wondershare.com/mobile-tracker/child-phone-tracker-apps.html
what phone do you have? check your apps in the play store, under "My Apps". it should list all of your app purchases.