When you use apps on your phone, various data is stored temporarily in the phone memory. If your phone runs out of memory, it may help deleting this data.
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Apps & notifications.
Press SEE ALL APPS.
Press the required app.
Press Storage and cache.
Press CLEAR CACHE.
Press the Home key to return to the home screen.