Sonys Press conference from MWC took place end of February
If you missed it you can watch it here.
Please join the discussion here and share your thoughts on what was anounced here.
MWC 2019 discussion.
The Xperia XA Ultra seems to suffer from this problem a lot whether it's just turning the phone off and back on again or just restarting the phone to clear the cache.
Unfortunately when this happens all you can do is reinstall the software using the Sony companion.
Hold both the volume up and down buttons as well as the power button to restart the phone, making sure the USB is connected already (ignore all other info where they say you need to connect the USB AFTER you restart the phone). Once the phone switches off let go of all other buttons but keep holding the DOWN volume button. The Sony companion software will now recognise the phone and you can restore as normal.