My mobile phone was a problem when Xiaomi 2s updated the system at 12 13. I was playing with my mobile phone when I updated (1), and I sent a short message myself.

For 1, it is best not to do other operations when the system is updated, so as to avoid abnormal situations. See that you have solved the problem after the restart. For 2, you can find the default application settings in System Settings-Applications to change the default application you open according to your preference. For 3, this may be just a feeling, but there may be some bugs in the development version. Please wait until the next upgrade before observing.