The phone is 'optimizing network' and constantly restarts (1 reboot per 1-2 days)
I have Xperia XZ2 Compact dual sim.
Android version 9
Build number 52.0.A.8.14
All latest updates have been installed.
My phone shows message that it 'optimized network settings' (I don't know the exact message in english) and requires the reboot. It happens constantly one time per 1-2 days. After reboot the phone switches the default sim card for calls, sms and data to other sim card than was selectes before reboot. Also the phone looses the mobile data connection.
To restore the mobile data connection I must turn-on Wi-Fi, get the phone to download the mobile provider settings by Wi-Fi, switch the default sim for calls, sms and data and reboot the phone manually again.
Every now and then my phone gives a message "the data settings are being optimized". The only thing I can do when that happens is press ok, which leads to an immediately reboot of the phone. After de reboot the dual SIM settings aren't correct anymore. Sim 2 is my data sim, but data is switched back to sim 1. After correcting that i have to reboot again.
Also after every reboot Volte on my second sim reactivates, but i don't ue that sim for calling.