This may because of one of two reasons-
# Your phone clears its cache without displaying a pop-up message saying that it completed the task. Some phones are like this.
# Some apps are programmed to not clear cached information that is necessary to receive the services you want to use.
A good way to reset your phone back to its original state is to perform a full factory reset. This will clear the phone’s cache, remove any malware, and perform any needed updates at the same time. You can do this in your phone’s Settings.