Have you tried this?
Restarting your Xperia device will close all open apps. Your device will run faster and smoother and there will be more memory available.
To restart your device
If restarting your device didn't help, then try this:
Update
The quickest and easiest way to solve many performance issues.
Software repair
Solves issues with an unresponsive device, or a forgotten screen lock.
Safe mode
In Safe mode, your device starts with only the original pre-installed software and apps running. If the performance improves in Safe mode, it’s likely that one or more downloaded apps are causing the issue. Restart your device to exit Safe mode and then uninstall the identified apps.
To enable Safe mode (Android 8.0)
Long press the power key.
Touch and hold Power off until the device starts to power off.
Update
New software releases bring you the latest and improved features and functions, as well as potential bug fixes. A notification in the status bar will let you know when a new software update is available. You can also check for new updates manually.
To check for and install new software (Android 8.0)
Find and tap Support > Software > Software update.
If a system update is available, tap UPDATE.
Software repair
A software repair can be used if you can’t start your device, or if you have forgotten your screen lock password, pattern or PIN code. All user data will be deleted, including downloaded apps, photos, and device settings.
To perform a software repair (Android 8.0)
Make sure you know your Google account username and password, used on your device.
Back up your content to a non-encrypted memory card or other non-internal memory.
Make sure that Xperia Companion is installed on your PC or Mac.
Open the Xperia Companion software on the computer and click Software repair on the main screen.
Follow the on-screen instructions to reinstall the software and complete the repair.
Reset
A factory data reset will revert your device to its initial state and your latest software version. All user data will be deleted, including downloaded apps, photos, and device settings.
To reset your device (Android 8.0)
Make sure you know your Google account username and password, used on your device.
Back up your content to a non-encrypted memory card or other non-internal memory.
Find and tap Settings > System > Reset.
Tap Factory data reset > Reset phone.
If required, draw your screen unlock pattern or enter your screen unlock password or PIN to continue.
To confirm, tap Erase everything.
